FP Essentials™ 379
Diagnosis and Treatment of Foot Conditions
Summarize the conservative treatment options for plantar fasciitis.
Analyze the role of steroid injection and radiofrequency therapy in treating plantar fasciitis.
Describe an approach to treating corns and calluses.
Cite a reason for avoiding surgery for recalcitrant calluses under the metatarsal heads.
Summarize the risk factors for plantar warts.
Cite evidence-based plantar wart treatment options.
Describe the optimal diagnostic strategy and treatment options for onychomycosis.
Summarize the causative factors for ingrown toenail.
Summarize the role of antibiotics in the treatment of ingrown toenail.
Analyze the surgical options for ingrown toenail.
Summarize the role of imaging in diagnosing metatarsalgia.
Cite the nonsurgical options in the treatment of metatarsalgia.
Key Practice Recommendations
- For initial treatment of plantar fasciitis, use conservative (nonsurgical) measures, including routine stretching of the plantar
fascia and Achilles tendon, and use of night splints and orthoses.
- Use salicylic acid for initial treatment of plantar warts for 6 to 12 weeks.
- Use oral terbinafine 250 mg/day for treatment of dermatophyte nail infection: 12 to 16 weeks for toenails and 6 weeks for
- Use partial nail avulsion combined with phenolization in the treatment of ingrown toenail.
- Strength of evidence: SORT C
Source: McPoil TG, Martin RL, Cornwall MW, et al. Heel pain—plantar fasciitis: clinical practice guidelines linked to the international classification of function, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2008;38(4):A1-A18.
- Strength of evidence: SORT A
Source: Gibbs S, Harvey I. Topical treatments for cutaneous warts. Cochrane Database Syst Rev. 2006;(3): CD001781. Cochrane Database of Systematic Reviews.
- Strength of evidence: SORT A
Source: Gupta AK, Ryder JE, Johnson AM. Cumulative meta-analysis of systemic antifungal agents for the treatment of onychomycosis. Br J Dermatol. 2004;150(3):537-544 [Review].
- Strength of evidence: SORT B
Source: Rounding C, Bloomfield S. Surgical treatments for ingrowing toenails. Cochrane Database Syst Rev. 2005;(2):CD001541. Cochrane Database of Systematic Reviews.
This activity, FP Essentials™, has been reviewed and is acceptable for up to 60 Prescribed credit(s) by the American Academy of Family Physicians. AAFP accreditation begins December 1, 2010. Term of approval is for two year(s) from this date with the option of yearly renewal. This monograph is approved for 5 Prescribed credit(s). Credit may be claimed for two years from the date of each monograph.
The AAFP is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
The American Academy of Family Physicians designates this education activity for a maximum of 5 AMA PRA Category 1 credit(s)(TM). Physicians should only claim credit commensurate with the extent of their participation in the activity.
Walk a mile in another person’s shoes often enough and you will not only know more about the human condition, you will likely have sore feet. Although the foot is a complex system of 26 bones, 33 joints, 20 muscles, and over 100 ligaments, it seems that feet were not really made for standing, and as Socrates noted, “When your feet hurt, your whole body hurts.”
The first known depiction of the treatment of sore feet (foot massage or manipulation) is a relief in the tomb of Ankhmahor, a physician in Egypt, dating to 2330 BC. The Chinese practiced foot massage and what is thought to be the beginning of reflexology over 5,000 years ago. Today, the treatment of sore feet includes a complex array of physical therapies, support and corrective devices, and sometimes surgery. This edition of FP Essentials™ addresses the diagnosis and treatment of many common foot conditions.
Despite having treated many patients with foot problems and personally having a condition described in each of these sections, I found particularly helpful the evidence review of the many treatment options for plantar fasciitis in Section One, the discussion in Section Two of second-line treatment (such as immunotherapy) for plantar warts, the enumeration and distinguishing features of the many causes of metatarsalgia in Section Three, and the review in Section Four of oral antifungal agents for onychomycosis. I hope you find this edition of FP Essentials™ as interesting as I did.
Mindy A. Smith, MD, MS, Associate Medical Editor
Professor, Department of Family Medicine
Michigan State University College of Human Medicine, East Lansing
Feet are at high risk of developing abnormalities due to repetitive trauma from everyday activities, exercise, poor-fitting footwear, and underlying medical conditions. Patients with diabetes, peripheral vascular disease, neuropathy, arthritis, autoimmune disorders, and various dermatologic conditions are at increased risk of developing foot conditions that restrict activities of daily living and limit mobility, often leading to disability.
Because there is no mandated curricular component in US medical schools, most medical education programs fail to introduce students to foot pathologies. Unless family physicians have developed adequate expertise in diagnosing and treating common foot conditions, patients are frequently referred to podiatry or orthopedic subspecialists for evaluation.
Proficiency in the evaluation and treatment of common foot conditions is important for family physicians. Heel and metatarsal pain; corns and calluses; common toenail abnormalities, including ingrown toenails and onychomycosis; and plantar warts are all commonly seen in the family medicine practice. This edition of FP Essentials™ provides an evidence-based guide to the diagnosis and treatment of these conditions to ensure family physicians possess the knowledge and skills necessary to care for patients with these conditions, and know when to refer patients for more specialized care.
Case 1. Dana is a 45-year-old moderately obese woman who presents to your office with right heel pain for 2 weeks after beginning a new running program to complement her efforts to lose weight. The pain generally does not manifest when she is running, but it returns in the evenings and when she is in nonweight-bearing positions. Her first steps in the morning cause exquisite pain at the distal medial border of the plantar aspect of the right heel that radiates along the plantar aspect of the foot. Dana has used ibuprofen intermittently, tried various stretching exercises, and purchased new running shoes, none of which have decreased the symptoms.
Definition and Epidemiology
The plantar fascia is a fibrous band of tissue originating from the inferior margin of the calcaneus and extending distally across the plantar surface of the foot to the metatarsophalangeal joints and the bases of the proximal phalanges. Plantar fasciitis, the most common cause of plantar heel pain, accounts for 11% to 15% of all foot concerns for which adult patients seek medical attention.Consensus favors a theory of mechanical overload and excessive strain that produce microtears within the plantar fascia, and resultant inflammation. However, patients with chronic heel pain have histologic findings that indicate the condition is predominantly a noninflammatory degenerative process, more appropriately termed plantar fasciosis.
More than 2 million US adults seek treatment annually for symptoms of plantar fasciitis, and approximately 10% of runners, as well as many other athletes, are affected by the condition.A study using the validated Foot Health Status Questionnaire found lower health-related quality-of-life scores for physical activity, social capacity, and vigor in patients with plantar fasciitis; age, sex, body mass index, and unilateral versus bilateral symptoms had no negative effect on the degree of impairment.
The peak age at onset of plantar fasciitis in the general population is between 40 and 60 years., Younger adults who regularly engage in running and other dynamic activities are also commonly affected, as are military personnel. Plantar fasciitis accounts for up to 10% of running injuries and is reported as bilateral in up to one-third of cases. Epidemiologic reports found no predilection by sex. While a specific etiology has not been defined, numerous conditions are associated with plantar fasciitis (Table 1). Other common causes of heel pain include bursitis, heel fat pad degeneration, nerve entrapment, periostitis, and seronegative arthritis.
Table 1 Common Conditions Associated With the Development of Plantar Fasciitis
Common Conditions Associated With the Development of Plantar Fasciitis
Achilles tendon stiffness
Improperly fitting footwear
Pes cavus (high-arched feet)
Pes planus (flat feet)
Rapid augmentation of running duration and intensity
Reduced dorsiflexion of the ankle
Unyielding running surfaces
Information from Vohra PK, Japour CJ. Ultrasound-guided plantar fascia release technique: a retrospective study of 46 feet. J Am Podiatr Med Assoc. 2009;99(3):183-190; Yucel I, Yazici B, Degirmenci E, et al. Comparison of ultrasound-, palpation-, and scintigraphy-guided steroid injections in the treatment of plantar fasciitis. Arch Orthop Trauma Surg. 2009;129(5):695-701.
In most cases, the diagnosis of plantar fasciitis can be made via history and clinical examination alone.start-up pain) and becoming less severe after the first few steps. Pain often gradually worsens throughout the day with increased duration of weight-bearing and high-impact activity. The pain of plantar fasciitis flares is often so severe that athletes must modify their workouts, and more sedentary individuals experience moderate disability.Pain is most often reported in the distal and plantar heel and anteromedial foot upon awakening, with greatest pain upon first heel strike (
Physical examination findings associated with plantar fasciitis include similar pain produced with:
Active and passive dorsiflexion of the talocrural joint
Palpation of the insertion of the proximal plantar fascia
Tarsal tunnel syndrome test—ankle passively, maximally everted and dorsiflexed while the metatarsophalangeal joints are maximally dorsiflexed and held in this position for 5 to 10 seconds
Windlass test (bowstring effect)—passive dorsiflexion of the toes while elevating the arch of the foot, which stretches the plantar fascial bands medially, centrally, and laterally.
There are no routine laboratory tests to aid in the diagnosis of plantar fasciitis. If considering arthritis, a serologic autoimmune evaluation might be warranted. Similarly, evaluation with x-ray or magnetic resonance imaging (MRI) is rarely necessary initially unless other causes of heel pain are suspected (Table 2).
Table 2 Differential Diagnosis of Heel Pain
Differential Diagnosis of Heel Pain
Calcaneal stress fracture
Cancer, primary or metastatic
Enthesopathies – unilateral or bilateral (suggests underlying spondyloarthropathy such as Reiter syndrome or ankylosing spondylitis)
Fat pad atrophy
Nerve entrapment or compression syndromes
Medial calcaneal branch of posterior tibial nerve
Tarsal tunnel syndrome
Paget disease, often accompanied with bowing of tibias and elevated serum alkaline phosphatase levels
Rupture of the plantar fascia
Information from Buchbinder R. Clinical practice. Plantar fasciitis. N Engl J Med. 2004;350(21):2162 [Review].
X-rays can be useful in diagnosing calcaneal heel spurs (Figure 1), yet their clinical relevance to plantar fasciitis is questionable because many calcaneal spurs are asymptomatic. One study found that 85% of patients with symptomatic plantar fasciitis and 46% of asymptomatic controls had calcaneal spurs on x-ray.
Radionuclide technetium scintigraphy (bone scan) can demonstrate a focal increase in activity at the plantar fascia insertion with between 60% and 98% sensitivity and 86% specificity, positive likelihood ratio of 4.2:7, and negative likelihood ratio of 0.02:0.46 for the diagnosis of plantar fasciitis. However, bone scan is rarely used unless a calcaneal stress fracture is suspected.
High-resolution ultrasonography (HRUS) can aid in the diagnosis of plantar fasciitis but is reserved for cases when guided corticosteroid injection is planned., In one study, HRUS confirmed the diagnosis of plantar fasciitis in 69% of patients, identifying the hallmark of perifascial edema in 53% of patients. Single photon emission computerized tomography (SPECT) and MRI can be used to visualize the plantar fascia and associated pathology when a diagnosis is in question but are not considered first-line diagnostic modalities.
The primary goal of plantar fasciitis treatment is to maximize pain relief and restore function. Prevention of the condition is often challenging. In approximately 90% of patients, pain due to plantar fasciitis will resolve within a year regardless of therapy.Expert opinion recommends weight loss, replacement of worn or poor-fitting footwear, and limitation of prolonged standing and repetitive impact. High-quality, randomized controlled trials (RCTs) with adequate statistical power are currently lacking for the majority of therapeutic interventions.
The initial treatment of plantar fasciitis should include conservative (nonoperative) measures such as routine stretching of the plantar fascia and Achilles tendon, nocturnal dorsiflexion splints (night splints), and orthoses. Acetaminophen or oral nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently advised as a cost-effective, first-line therapeutic option. These drugs decrease pain, but their effectiveness is limited unless combined with physical therapy, committed stretching regimens, night splinting, or orthoses.
Calf stretching is recommended to minimize pain due to plantar fasciitis and to relieve tension on the dorsal calcaneus, but optimal duration, frequency, and intensity have not been established. One RCT found no difference between sustained and intermittent calf stretching (standing at the edge of a step with the heel hanging off the edge, knee straight, and foot neutral); both treatment groups reported increased ankle dorsiflexion.Adhesive strapping or taping of the calcaneus and plantar foot surface has been shown to provide minimal to moderate short-term relief of heel pain but is most effective when combined with iontophoresis (a technique that uses a small electrical charge to deliver a drug or other chemical through the skin without the use of a needle) and calf stretching.
Night splint options range from custom-designed rigid materials to softer sock-like supports that use a Velcro strap to keep the ankle in a neutral position and the toes in slight extension.Patients often need time to adjust to wearing a night splint. A Cochrane review found limited evidence to recommend night splints for plantar heel pain of longer than 6 months’ duration, with or without NSAID therapy. Physician and patient preference often determine the type of night splint used (material and anterior or posterior placement); superiority has not been established with respect to patient-reported symptoms. Most patients report improvement in pain after 1 to 3 months, which is the recommended duration for a therapeutic trial.
A Cochrane review of custom-made orthoses for the treatment of plantar fasciitis yielded several conclusions.high arches), the use of custom foot orthoses decreased foot pain after an average of 3 months’ use. Among all adults with plantar fasciitis, however, custom foot orthoses might not improve foot pain more than prefabricated orthoses (after 1 year), routine plantar stretching or night splints alone (after 6 to 8 weeks), or physical therapy or stretching (after 2 weeks). An RCT that compared the low-cost foam (ethylene vinyl acetate [EVA]) prefabricated orthoses versus customized foot orthoses found that low-cost prefabricated and customized foot orthoses had similar efficacy in treating uncomplicated plantar fasciitis after 8 weeks.In adults with plantar fasciitis who have pes cavus (
A 2009 meta-analysis found that custom orthoses compared with no shoe insert improved both pain and function between the treatment period of 6 and 12 weeks, compared with treatment of less than 6 weeks.Compared with patients who used night splints, those who used orthoses reported significantly greater decrease in pain and improvement in function at a 12-week follow-up.
Corticosteroid injections of the plantar fascia are a treatment consideration only when conservative measures and orthoses have failed to decrease pain and increase function. They can be performed with techniques that are palpation-guided, ultrasound-guided, or scintigraphy-guided. Trials with small sample sizes found these injections to temporarily relieve heel pain in a majority of patients.These injections should be administered with caution because there is no evidence of superiority over other treatments, and the risk of fat pad atrophy with repeated injections may convert the self-limited problem of plantar fasciitis into one that is chronic.
There is no gold standard for the type or dose of corticosteroid and/or local anesthetic that should be administered; many different combinations have been used with no established superiority. One study recommends a mixture of 0.5 mL of betamethasone dipropionate and 0.5 mL of prilocaine hydrochloride; expert opinion is that the total volume administered should not exceed 1 mL to minimize the risk of fat pad atrophy and plantar fascia rupture.
In a randomized multicenter study of treatment of chronic plantar fasciitis, patients were randomized to 1 of 4 therapies: autologous blood alone, lidocaine with peppering, triamcinolone alone, and triamcinolone with peppering.Peppering is an injection technique that involves inserting the needle, injecting, withdrawing slightly without emerging from the skin, slightly redirecting, and reinserting; thus the injected area is peppered with 40 to 50 small injections. Participants in all therapy groups reported some symptomatic relief compared with baseline at intervals of 3 weeks and 6 months, with the greatest relief reported in those who received triamcinolone with peppering.
Extracorporeal shock wave therapy (ESWT), or orthotripsy, is an alternative therapeutic option for recalcitrant plantar fasciitis unresponsive to conventional nonsurgical therapies. Low-energy forms of the therapy can be performed in the ambulatory setting without local anesthesia, because the mechanism of action is acoustic waves that dissipate mechanical energy and act to stimulate soft-tissue healing and inhibit pain receptors.,
One small RCT of ESWT found a moderate success rate, defined as decreased pain at 12 weeks, in 61% of patients who underwent the treatment compared with 42% in the placebo group.A placebo-controlled RCT found success rates of 71% at 3 months and 77% at 12 months, with diabetes, older age, and documented psychological disorders negatively influencing outcomes. However, of 6 RCTs assessing overall efficacy, 3 trials showed no benefit and 3 showed only questionable benefit for symptom-related outcomes. Another RCT showed that manual physical therapy was superior and more cost-effective than ESWT in both short- and long-term follow-up periods. ESWT is considered to have only limited utility because the equipment required to perform ESWT is expensive, an ankle block is necessary prior to the procedure, and most insurance companies do not currently cover the procedure.
Surgical management of plantar fasciitis and chronic heel pain should be considered only after all other treatment modalities have failed to provide adequate pain relief and functional restoration. Ultrasound-guided release of the plantar fascia via microtenotomy allows for a minimally invasive approach and a more precise anatomical dissection that minimizes surgical risks and complications. In a study of 41 patients (46 feet), all patients reported statistically significant symptomatic improvements on the American Orthopaedic Foot and Ankle Society’s Ankle-Hindfoot Scale (a 100-point scale that grades ankle, subtalar, talonavicular, and calcaneocuboid joint levels) 4 weeks postsurgery, yet 42% of patients reported heel hypoesthesia postoperatively and 18% of patients continued to experience heel pain with weight bearing.Comparatively, older trials that evaluated the efficacy of open fascial release with resection of the fascia found that 7% of patients reported unrelenting heel pain, while 11% of patients who underwent fascial release and calcaneal osteotomy had unresolved heel pain.
Case 1, cont’d. Dana lost 7.7 kg (17 lb) over several months through dietary modification. X-ray results of the right foot are unremarkable. She began using night splints but stopped after 1 week because the discomfort disrupted sleep. She then tried prefabricated foam orthoses, which provided only minimal relief. Next, Dana was given customized orthoses and has continued routine stretching exercises with noticeable improvement in pain. She continues to be physically active and runs without significant limitations.
Corns, Calluses, and Plantar Warts
Case 2. Katherine is a 52-year-old healthy woman who presents with bilateral foot pain for the past year. Her job as a file clerk requires that she stand most of each day. Vital signs are normal, but the body mass index is minimally elevated (27 kg/m2). Katherine is wearing 3-inch heels. Examination of the left foot reveals a whitish, macerated lesion between the third and fourth digits. The right foot has a large area of thickened skin along the second through fifth metatarsal heads.
Epidemiology of Corns and Calluses
Hyperkeratotic lesions (corns and calluses) are common foot-skin conditions that can cause significant pain and morbidity. Although the incidence in the general population is not well defined, debridement of hyperkeratotic lesions accounts for approximately 75% of podiatry subspecialist referrals.Corns and calluses affect 33% to 68% of community-dwelling individuals older than 65 years. These lesions are associated with impaired gait speed, impaired balance, and decreased independence. Female sex, hallux valgus, toe deformities, increased ankle flexibility, and amount of time spent on the feet are all associated with plantar hyperkeratotic lesions. Obesity, forefoot pain, and foot dominance have not been linked with corns and calluses.
Corns are sharply demarcated lesions that are round to oval, yellowish gold, uniform, well circumscribed, and have a visible translucent core composed of thickened stratum corneum. Subdermal hemorrhage into a corn may result in dark red, brown, or black discoloration. Corns occur as a hyperkeratotic protective response to mechanical trauma and may develop as a result of shear force, friction, or high skin pressures from deformity (eg, hammer toe) or ill-fitting footwear.
Corns are classified as hard (heloma durum, or digital corn) or soft (heloma molle). Hard corns are most common on the dorsolateral fifth toe or second through fifth toe dorsal interphalangeal joints (Figure 2). This dry, horny hyperkeratotic mass has a hard central core. Soft corns (heloma molle, or interdigital corns) can be extremely painful and are the result of absorption of moisture from sweat leading to maceration and possible secondary fungal or bacterial infection. Soft corns can develop between any toes but are most common between the fourth and fifth toes.
The differential diagnosis includes porokeratosis (clonal disorder of keratinization), warts, digital bursa, and epidermal malignancy. Corns are distinguished from plantar warts by several features.Corns develop slowly over months or years and are usually located over bony prominences. Skin lines pass through corns. When corns are pared with a scalpel, no end arteries are seen.
Case 2, cont’d. You diagnose a soft corn on Katherine’s left foot and a callus over the right plantar second through fifth metatarsal heads.
A simple method is to debulk the corn using a No. 15 scalpel blade and apply a nonprescription salicylic acid plaster (40%) trimmed to the size of the lesion and left in place for 48 to 72 hours. The area should be kept dry. When the plaster is removed, the white (dead) skin is pared using a pumice stone or metal file. The plaster is then replaced every 48 hours for 14 days or until the lesion resolves. Plaster should be avoided in patients with peripheral neuropathy, because they may not feel pain with improper patch placement, and damage to normal skin can result. In patients with diabetes or peripheral vascular disease, if plaster is left on too long, acid may erode through the dermal skin layer, causing ulceration that can progress to osteomyelitis.
Orthoses redistribute mechanical stresses to heal corns. Heloma shields, silicone toe splints, and ring-shaped corn pads relieve pain around the corn’s central keratin plug. Interdigital soft corns are treated using interdigital wedges made from cross-linked polyethylene foam or silicone orthodigital splints; wider shoes may be needed if the addition of orthoses further increases pressure on the corns.
A callus is a diffuse thickening of the stratum corneum in response to friction, pressure, or irritation. Calluses are generally broad-based and diffusely hyperkeratotic with undefined margins. The lesions are most often found under the metatarsal heads. The 2 basic types of calluses are diffuse-shearing and discrete-nucleated; the latter are often confused with corns because they contain a central keratin plug.
Treatment for calluses and corns is similar. Diffuse painless hyperkeratotic lesions are treated with warm-water soaks followed by pumice-stone debridement. Sharp-scalpel debridement by a physician or podiatry subspecialist is also a common treatment strategy, although evidence-based guidelines are unavailable regarding optimal debridement frequency or effectiveness. One randomized controlled trial (RCT) (N=38) found no difference between scalpel and sham debridement of plantar callus in patients with rheumatoid arthritis.Neither localized foot pressures over the callus nor gait function significantly improved following normal debridement.
Prevention of Corns and Calluses
Improperly fitting shoes are a major cause of corns and calluses, and low-heeled shoes with a soft, wide toebox are recommended. Lateral fifth digit corns and interdigital soft corns may be relieved with extra-wide shoe widths. Hammer or claw toes may require extra shoe depth. Loose shoes may cause shear to the lateral weight-bearing areas of the sole, causing a marginal callus or heel fissure.
For a lone plantar callus over a metatarsal, a pad applied proximally to the affected metatarsal head reduces underlying skin pressure. Offloading shoe inserts provide pressure relief of the forefoot area; customized, full-length shoe inlays are also available.
Recalcitrant or Recurrent Lesions
Obtaining an x-ray of the foot to evaluate for underlying bony abnormalities is prudent with recalcitrant or recurrent lesions. Surgery to change foot mechanics or alleviate bony prominences is indicated only when conservative measures fail. Resection of the prominent condyles, or fifth-toe excision arthroplasty of the proximal phalanx, is an option for hard corns of the fifth toe and soft interdigital corns.Calluses under the metatarsal heads should be treated conservatively because the callus may transfer to an adjacent metatarsal head after metatarsal osteotomy.
Case 2, con’t. You recommend Katherine change footwear from high heeled to flat-heeled shoes with a wide toebox. You tell her to soak the feet nightly in warm water and use a pumice stone on the callus; you also prescribe a silicone splint for the soft corn. After 1 month, the callus and corn have resolved.
Epidemiology of Plantar Warts
Case 3. Jim is a 10-year-old boy who presents with several thickened rough patches on the feet that developed after he joined a swim team. Several family members have similar lesions on the feet. When you scrape the lesion with a No. 15 scalpel, small punctate areas of bleeding are seen.
Plantar warts (verruca plantaris) are caused by human papillomavirus (HPV), most commonly subtypes 1, 2, 4, 27, and 57. Warts are rarely seen in infants; 10% of children and young adults have the condition.Warts are more common in females; peak incidence is age 13 years in females and age 14.5 years in males. One study of 1,465 Dutch schoolchildren ages 4 to 12 years found that 33% had warts: 9% had hand warts, 20% had plantar warts, and 4% had both. Increased risk of warts was found if the child had a family member with warts (odds ratio [OR]=1.9; 95% confidence interval [CI]1.3-2.6) and in children who had a high percentage of school classmates with warts. Environmental factors such as walking barefoot and using public showers or swimming pools were not related to wart transmission. This contradicts traditional plantar wart prevention advice of wearing footwear in communal showers and athletic changing areas.
Nongenital warts in immunocompetent individuals are not harmful. They often resolve spontaneously over months to years as a result of natural immunity and can be monitored over time. Still, warts may be unsightly and embarrassing, be a reservoir for HPV transmission, and may cause pain. Many patients opt to have plantar warts treated for these reasons.
Diagnosis of Plantar Warts
Plantar warts appear as verrucous lesions on pressure points of the soles of the feet. They are often skin colored and rough. They may occur singly or as mosaic plaques when multiple firm papules coalesce. They usually obscure normal skin markings, unlike corns or calluses. Paring the hyperkeratotic debris of a plantar wart reveals thrombosed capillaries (seeds). The differential diagnosis of verrucae is listed in Table 3.
Table 3 Differential Diagnosis of Verrucae
Differential Diagnosis of Verrucae
|Condition||Differentiating Features From Verrucae|
Acrochordon (skin tag)
Pedunculated, flesh colored, and soft in consistency rather than rough
More common on palms or soles; consider biopsy for nonresolving or atypical lesions
Does not usually obscure skin lines
No thrombosed capillaries (seeds) after scalpel scraping
Wickham striae, oral lacy appearance and symmetric distribution
Pigmented, stuck-on appearance
Can have horn cysts
Squamous cell carcinoma
Lesions in sun-exposed areas
Treatment of Plantar Warts
Plantar warts are more resistant to treatment than common warts. Evidence-based guidelines on treatment are limited. No single type of therapy achieves complete wart remission in every patient.
Topical salicylic acid should be used as the initial treatment for plantar warts. In a Cochrane review, 13 trials compared topical preparations of salicylic and lactic acid, salicylic acid only, or lactic acid only.Pooled data from 5 trials showed superior cure rates of these preparations (73%) versus placebo (48%). Treatment duration ranged from 6 to 12 weeks.
Salicylic acid dissolves wart intercellular cement and causes desquamation of the horny layer of skin without affecting normal epidermal cells. Nonprescription liquid preparations are applied daily; salicylate plaster patches are applied and changed every 48 hours. Advantages and disadvantages of salicylate preparations are listed in Table 4.
Patients are advised to soak the foot in warm water for 5 to 10 minutes daily then dry and debride using an emery board or pumice stone. Disposing the debridement instrument after use is important; 1 study found HPV DNA on 10 of 10 emery boards used to scrape plantar warts; this DNA was detectable immediately and several hours after use.HPV transmission risk may be reduced if an emery board is used once and discarded.
Two small trials comparing placebo and topical dinitrochlorobenzene (2% DNCB) directly applied to a wart showed cure rates of 38% (15 of 40) and 80% (32 of 40), respectively.Participants in these 2 small RCTs reported sensitivity reactions, and second treatment commonly caused pain and blistering. DNCB is also mutagenic.
Case 3, cont’d. Jim has used salicylic acid patches for 3 months, but the warts are still present. His mother asks what other options are available.
Cryotherapy using liquid nitrogen is recommended as second-line therapy when topical treatment fails. Liquid nitrogen, with a temperature of -196°C (-321°F), is more effective than nonprescription freezing products (eg, Verruca-Freeze) that reach a temperature of -70°C (-94°F).
Warts are generally frozen from 10 to 30 seconds until a 1- to 2-mm ball of ice surrounds the lesion. Comparison of cryotherapy trials is difficult because of significant variations in freeze times, treatment intervals, and duration between protocols. Aggressive cryotherapy (10 seconds or greater) appears to be more effective than gentle cryotherapy (10 seconds or less) (cure rate of 52% versus 31%), although pain and blistering are more common with aggressive cryotherapy.No significant difference in cure rates is seen whether cryotherapy is performed at 2-, 3-, or 4-week intervals. There is no significant benefit to prolonging cryotherapy for plantar warts for longer than 3 months.
One study comparing duct tape occlusion with 10-second cryotherapy in 61 individuals ages 3 to 22 years found higher resolution rates with duct tape occlusion (85% versus 60%).The mechanism of action is not completely understood, but theories include direct-tape debridement of the epidermis (removing skin and attached virus) and tape triggering of the immune system through mechanical or chemical skin irritation resulting in wart destruction.
Another trial of duct tape (N=103) showed no statistically significant benefit.In this trial, clear duct tape was used instead of silver; different adhesives in the 2 tapes may account for the results.
Duct tape is occlusively applied to dry skin, left in place for 6 days, removed, and reapplied the following morning after wart debridement with an emery board. Treatment continues for 2 months or until wart resolution. Most warts that resolve do so within 1 month of treatment. Duct tape can also be used in conjunction with topical treatments, including salicylic acid.
Imiquimod 5% cream is a cytokine-stimulating immunomodulator used to treat genital warts. Although expensive and not well studied for the treatment of plantar warts, imiquimod has shown some benefit when used 3 times a week following plantar wart debridement.
The immunomodulator 5-fluorouracil (5-FU) inhibits DNA and RNA synthesis and prevents HPV replication. In an RCT, applying 5-FU cream 2 times daily in conjunction with debridement and tape occlusion effectively treated plantar warts in 19 of 20 patients.Average time to cure occurred at week 9 of treatment in 2 other RCTs but appears to have no advantage over other simpler, topical treatments.
Trials of intralesional bleomycin injection (1.5 U/mL) for plantar warts show varying cure rates (16% to 94%).Bleomycin is generally reserved for use after failure of conservative therapy. Authors of a Cochrane review found insufficient evidence for effectiveness.
High-dose cimetidine (20 to 40 mg/kg day) might function as an immunomodulator by inhibiting suppressor T-cell function, increasing lymphocyte response, and improving cell-mediated immunity. In open-label studies, high-dose treatment resolved 82% of recalcitrant warts.Three small RCTs found cimetidine to be no more effective than placebo.
Intralesional injection of mumps, Candida, or Trichophyton antigens has been explored as a wart treatment. In 1 RCT of refractory warts (N=201), up to 5 injections were administered into the largest wart at 3-week intervals. Sixty percent of participants injected with antigen either with or without interferon had resolution of at least 1 wart compared with a 24% resolution rate in patients injected with interferon or saline alone. Because of the expense and number of injections required, this therapy has no significant advantages.
Lasers used for treating plantar warts include carbon dioxide, erbium:YAG, Nd:YAG, and pulsed dye lasers.Lasers induce thermal damage that destroys virally infected tissue. Face masks and eye shields should be used during treatment to prevent smoke-plume-mediated wart transmission. Anesthesia might be required depending on lesion thickness. Short laser pulses of 0.45 ms are most effective. Gray skin discoloration and eschar formation occur within 10 to 14 days. Plantar warts might require multiple treatments every few weeks. Pulsed dye laser therapy caused wart remission in 48% to 95% of cases in several small prospective trials; however, another trial demonstrated no statistically significant differences in cure rates compared with cryotherapy or cantharidin (66% versus 70%).
Surgical management using a sharp, spoon-shaped tool or 4- to 7-mm ring curettage and cautery of the base is sometimes useful when first- and second-line therapies are ineffective. Anesthesia is necessary for larger lesions. Scarring and possible contractures on the soles make surgery a consideration only after less invasive treatments fail.
Case 3, cont’d. Jim undergoes cryotherapy using a 30-second, freeze-thaw-refreeze approach. He follows up every 2 weeks for a total of 3 sessions. After 2 months, he has resolution of the plantar warts.
Diagnosis and Treatment of Toenail Conditions
Case 4. Frances is a 55-year-old woman with poorly controlled type 2 diabetes who presents for a routine follow-up visit with right great toe pain. During the physical examination, you suspect onychomycosis because several of the toenails are thickened and discolored yellowish-brown. More than one-half of the right great toenail is thickened and discolored, and the medial edge is ingrown with erythema of the surrounding skin.
Epidemiology and Classification
Onychomycosis is a chronic fungal infection of the nails that accounts for up to 50% of all nail disorders in the United States.An outpatient-based, cross-sectional survey of patients without previously diagnosed onychomycosis identified a prevalence of 8.7% in the total population and 6.5% in female and 13.3% in male subgroups. Risk factors for development of onychomycosis include a history of tinea pedis, a family history of onychomycosis, age greater than 60 years, nail trauma, peripheral arterial disease, current smoking, diabetes, and immunosuppression including HIV infection.
Several classifications of onychomycosis exist based upon route of fungal invasion (eg, underside of nail, cuticle) and clinical manifestation (eg, white superficial, total dystrophic).Distal lateral subungual onychomycosis is the most common form, characterized by fungus that infects and invades the underside of the nail plate, migrating proximally through the nail matrix. Once infected, bacteria and other fungi proliferate, causing a yellowish-brown nail appearance.
The dermatophytes Trichophyton rubrum (91%) and Trichophyton mentagrophytes (8%) are the most common infecting organisms. Nondermatophyte fungi also causing onychomycosis include Scopulariopsis brevicaulis, Fusarium species, Aspergillus species, Scytalidium hyalinum, and Onychocola canadensis; these account for 1.4% to 17.5% of cases. Candida albicans and Candida parapsilosis are the predominant yeast forms linked to onychomycosis and the most common organisms affecting fingernails.
The differential diagnosis of onychomycosis includes psoriasis, lichen planus, bacterial infections (eg, Pseudomonas aeruginosa), contact dermatitis, trauma, nail-bed tumors, drug reaction (eg, tetracycline), yellow nail syndrome (nail thickening and yellowish discoloration associated with systemic disease, most commonly lymphedema and respiratory compromise), and idiopathic onycholysis. Psoriasis can be differentiated from onychomycosis by the presence of fine pitting on the nail surface, bilateral involvement of fingernails, nodules on the distal joints of the toes and fingers, and/or bursitis; the 2 conditions may coexist.
The diagnosis of onychomycosis is usually made by visual inspection without confirmatory testing., Accurate sampling of infected nail and tissue is imperative to maximize diagnostic yield. A sample is commonly obtained from the most distal edges of the nail; however, this is where the viability of dermatophytes is lowest. An optimal sample must be from a site proximal enough to contain active fungal elements. One study determined that drilling a 3-mm vertical hole in the nail to act as an electrical curette was superior to either standard curettage from the nail bed or clipping the distal nail edges.However, confirmation of fungal infection prior to initiation of pharmacotherapy is considered the gold standard based upon expert opinion considering cost-effectiveness and potential adverse drug effects.
Direct microscopy with potassium hydroxide (KOH) preparation is the standard office-based laboratory detection method with a positive predictive value (PPV) and negative predictive value (NPV) of 88% and 58%, respectively; however, it does not allow for pathogen identification., Fungal culture should be obtained after the KOH preparation and yield a PPV and NPV of 90% and 43%, respectively. One study found that polymerase chain reaction analysis of skin scale and nail-bed specimens yielded positive detection rates of 95% to 99%, respectively, compared with detection rates of 67% and 33%, respectively, using culture isolation.
The decision to treat onychomycosis centers on potential complications of the condition (eg, ingrown nail, cosmesis), cost considerations, and potential adverse effects in conjunction with the patient’s comorbidities. It is reasonable to not treat patients who have limited nail infection and no associated symptoms. Standard recommendations to minimize household spread include avoidance of sharing footwear and nail clippers. Drug treatment has not been studied for the purpose of minimizing transmission risk.
Mechanical toenail debridement was standard therapy for onychomycosis before widespread use of antifungal drugs. Outpatient removal of dystrophic and unsightly portions of onychomycotic nails with the use of burring tools is well tolerated without local anesthesia and can be performed by trained physicians. Debridement requires interval therapy, and complete cure is rare.Complete removal of an infected toenail should be considered for severe pain or when other standard therapies have failed.
Topical monotherapy is an option when less than one-half of the toenail or fingernail is affected without involvement of the matrix or surrounding skin.Ciclopirox 8% solution applied daily for up to 6 months is the only currently FDA approved topical nail lacquer for onychomycosis treatment. Two randomized controlled trials (RCTs) found cure rates of 29% to 36% after 48 weeks of therapy in patients with isolated dermatophyte infections, while 1 open multicenter trial found a cure rate of approximately 90% after 6 months of therapy in patients with nondermatophyte infections. Common adverse effects include periungual and proximal nail fold erythema; these often resolve spontaneously with treatment cessation.
Systemic oral antifungal therapy results in higher cure rates than topical therapy for onychomycosis. Oral terbinafine (250 mg/day for 12 to 16 weeks for toenails and 6 weeks for fingernails) should be used to treat onychomycosis.It is the most well-tolerated and cost-effective treatment for dermatophyte nail infection (average cure rate of 76%). Treatment with pulse-dose terbinafine (500 mg/day for 1 week per month for 3 months) can increase drug adherence and minimize adverse drug reactions. One RCT comparing continuous terbinafine (250 mg/day for 3 months) to pulse-dose terbinafine found cure rates of 71% and 59%, respectively. Another RCT found that intermittent terbinafine had cure rates superior to itraconazole pulse therapy (84% and 57%, respectively) but a cure rate (78%) similar to continuous terbinafine. Hepatic injury is rare, but caution is advised in patients taking drugs metabolized by the liver and known to increase transaminases (eg, statins).
To date, there is no evidence to support widespread treatment of household or close contacts. Expert opinion suggests that risk of recurrence can be minimized through patient education regarding proper nail trimming, use of cotton or other absorbent sock materials, complete drying of feet after bathing, and use of antifungal foot powder in footwear.
Epidemiology and Pathophysiology
Onychocryptosis, or ingrown toenail, is seen in 20% of patients presenting to family physicians with foot concerns.Table 5). During adolescence, foot perspiration contributes to toenail softening, allowing nails to crack and split. As adults mature, the natural aging process causes toenail thickening, which exerts pressure on the skin at the sides of the nail plate and increases the likelihood of puncture and ingrowing.Ingrown toenail occurs when either the medial or lateral nail plate punctures the periungual skin, resulting in an acute to chronic unsightly and painful condition marked by infectious, inflammatory, and reparative stages. The hallux nail is most commonly affected; mild to severe pain, with varying degrees of infection and disability, occurs. Expert opinion states the most common cause of ingrown toenail is improper nail trimming (rounding the nail and cutting it too short) or tearing off the edges. Several causative factors have been suggested for why certain individuals develop ingrown toenail (
Table 5 Risk Factors and Commonly Proposed Etiologies of Ingrown Toenail
Risk Factors and Commonly Proposed Etiologies of Ingrown Toenail
Poor foot hygiene
Repetitive trauma (eg, kicking, running)
Systemic disorders (eg, diabetes, cardiac/thyroid/renal disease)
Improper trimming/tearing of toenail
Thin, flat nails
Inadvertent trauma (eg, dropping objects on toe, kicking/stubbing toe)
Wide nail folds
Information from Heidelbaugh JJ, Lee H. Management of the ingrown toenail. Am Fam Physician. 2009;79(4):303-308, 311-312 [Review].
Ingrown toenail is commonly characterized by a nail bed that is too narrow for the nail plate.,The condition is typically classified along the continuum of mild to moderate to severe, based upon clinical manifestation and acuity. Mild to moderate cases are characterized by nail fold and periungual tissue edema, minimal erythema, and pain with minimal pressure. Moderate to severe cases are associated with increased swelling, seropurulent drainage, infection, and ulceration of the nail fold. Chronic ingrown toenail is characterized by marked nail fold hypertrophy and prominent granulation of tissue that may cover the medial or lateral nail fold.
Conservative therapy can be used in patients with mild discomfort and erythema without purulent drainage (Figure 3). Twice-daily soaking of the affected toe in warm, soapy water or warm water with 5 to 10 mL (1 to 2 tsp) of magnesium sulfate, then application of topical antibiotic ointment or a topical mid- to high-potency steroid for several days, offers resolution in many mild cases. A study of the use of wisps of cotton under the ingrown lateral nail edge using a nail elevator or a small curette found a 79% rate of symptomatic improvement over a period of 24 weeks. Dental floss inserted obliquely under the ingrown nail edge is effective in relieving mild cases of ingrowing after a few days to weeks, offering moderate pain relief and resumption of normal activities; infection risk is not increased.
The use of oral antibiotics in the treatment of ingrown toenail is based solely upon historical practice.Staphylococcus aureus and less frequently by gram-negative organisms (eg, Pseudomonas) and Streptococcus species. One RCT found no significant difference in healing times between groups that received concomitant antibiotics and surgical therapy compared with surgical therapy alone over a 2- to 3-week period. Initial treatment with oral antibiotics before surgical therapy has not been shown to decrease healing times and is associated with a delay in surgical therapy, and thus may increase clinical healing time.Infections of ingrown toenail are most commonly caused by
Unilateral partial nail avulsion and matricectomy is an effective treatment in the majority of cases of ingrown toenail (acute and chronic). One caveat is that contralateral ingrowing may develop as the remaining portion of the nail plate spontaneously repositions itself due to pressures on the toe from daily activities and exercise.If an infection of the lateral nail fold develops, an oral antibiotic (eg, cephalexin 500 mg orally 4 times/day for 5 to 7 days) should be prescribed that covers common skin flora.
The best evidence supports partial nail avulsion with phenolization of the nail matrix (application of 80% to 88% phenol solution to the nail matrix for 30 seconds, followed by application of 70% isopropyl alcohol to neutralize the phenol for 3 rounds) for chronic and recalcitrant cases.Phenolization should not be performed when an active infection manifests, because the risk of postoperative infection increases. Partial nail avulsion compared with surgical excision of the nail matrix has been shown to be equally effective. A Cochrane review found that partial nail avulsion combined with phenolization is more effective at preventing recurrence but has a slightly increased risk of postoperative infection compared with surgical nail avulsion with phenolization. Phenol has both antiseptic and anesthetic properties, but its use can cause tissue damage, leading to infection and delayed postoperative healing. However, 1 RCT found that partial nail avulsion with phenolization yielded better results than partial avulsion with nail matrix excision, without an increase in infection risk.
Additional surgical therapies for ingrown toenail include partial matricectomy via electrodessication, radiofrequency ablation, and matrix ablation with carbon dioxide (CO2) laser.Advantages of these techniques compared with the standard surgical techniques mentioned previously include less bleeding, reduced postoperative pain, sterilization of infected tissue, and limited thermal damage to adjacent tissues (CO2 laser). Disadvantages include a prolonged period of re-epithelization and healing of the tissues by secondary intention, which can require local wound care for several weeks. One small retrospective study found that lateral foldplasty, whereby the lateral skin fold is resected sparing the nail edge and sutured closed, with or without partial matricectomy, yields good cosmesis. To date, none of these procedures has been directly compared with the standard accepted methods with regard to efficacy, recurrence, cost, or healing times.
Case 4, cont’d. You suggested that Frances soak the right great toe in warm, soapy water and apply topical antibiotic ointment several times/day for 1 week, but she had no significant decrease in pain. You also used a potassium hydroxide preparation for curettage from the proximal right great toenail and sent the specimen for fungal culture; both sets of results were positive for fungi. When Frances returns for follow-up, you perform a partial matricectomy with phenolization and provide wound care instructions. You also prescribe terbinafine 250 mg/day for 12 weeks to treat onychomycosis.
Metatarsal Pain: Etiologies and Treatments
Case 5. Erna, a 45-year-old woman, presents with pain in the ball of the right foot. It has been gradually worsening over the past several months and is worse after a long day of work, during which she stands the majority of the time. She is wearing high-heeled shoes. On examination of the feet, you observe that Erna has a very flat right foot and a bunion on the right foot.
Definition and General Approach
Metatarsalgia (metatarsal pain) is forefoot pain in the metatarsal region. It is frequently associated with a range of forefoot conditions. Tight-fitting or high-heeled shoes and inherited structural variants (eg, flat feet, high-arched feet) may cause metatarsal pain. X-rays can rule out fractures or dislocations and evaluate foot anatomy for inherited or acquired structural abnormalities, although a trial of conservative therapy first is also an option. Further evaluation might require magnetic resonance imaging (MRI).
Conservative, nonoperative management includes analgesics, footwear modification, orthoses, stretching and strengthening exercises, and corticosteroid injection.
Caution should be used with long-term nonsteroidal anti-inflammatory drug (NSAID) use; alternate medications (eg, acetaminophen) may be preferred in the setting of comorbid cardiac, renal, or gastric disorders. Studies comparing the effectiveness of NSAID versus non-NSAID analgesia are needed. Surgical referral might be warranted in cases of refractory pain or disability.
Hallux valgus involves valgus angulation of the first metatarsophalangeal (MTP) joint with a medial prominence of the first metatarsal head (bunion) and forefoot widening. Presentation ranges from normal anatomy with cosmetic variation to severe deformity and disability. Pain from superficial irritation is exacerbated by tight-fitting footwear. Women older than 30 years who have significant family history of the condition are most often affected. Hallux valgus may manifest in combination with other conditions including hammer toe, central metatarsalgia, severely pronated foot, or ingrown toenail.
Hallux valgus is readily apparent on foot examination. Irritation due to shoe wearing may cause painful bursitis over the first MTP joint. Gait analysis may reveal excessive pronation.X-rays are not necessary for diagnosis, but they can classify severity.
Typical initial treatment options are footwear modification (eg, lower heels, greater width) or bunion pads and analgesics. Other conservative treatments include braces and foot exercises to stretch and strengthen affected soft tissue. Athletic-shoe stretching may provide relief by offloading high-pressure areas, including the medial prominence.
Orthoses to correct abnormal foot function can be considered if initial treatments fail. One study comparing patients who used custom orthoses with controls found a significant difference in pain at 6 months, although no difference was seen at 12 months.In the same study, patients in the surgical group had significantly decreased pain levels compared with those in the orthoses at 6 and 12 months.
Surgical management is considered for failed conservative treatment or progressive or severe disease. Multiple surgical techniques are available, including exostectomy (removal of the bony prominence), metatarsal and/or proximal phalanx osteotomy, and first MTP joint arthroplasty with or without joint replacement.Corrective surgery can cause MTP joint stiffness; patients should be counseled about this prior to surgery. Minimally invasive surgical techniques can improve outcomes but have a similar risk for MTP joint stiffness; physical therapy can be beneficial. ,
Hallux rigidus involves progressive first-MTP joint arthritic degeneration with decreased range of motion, particularly with dorsiflexion. Adaptive foot supination to offload the first MTP increases risk for lateral metatarsalgia and ankle-inversion injury. Joint inflammation, synovitis, osteophyte formation, and impingement by tight-fitting footwear cause MTP pain. Repetitive dorsiflexion of the first MTP joint worsens symptoms. Individuals who engage in repetitive squatting and dancers who stand on the balls of their feet are particularly at risk.,
Physical examination of the foot can reveal first-MTP joint dorsal prominence with tenderness along the joint line, decreased range of motion, palpable osteophytes on the dorsal surface, and irritation of the overlying skin. Forced dorsiflexion reproduces pain. Strength, sensation, and reflexes are usually normal.
X-rays can show osteoarthritis with joint space narrowing and misalignment, large dorsal osteophytes, and metatarsal and proximal phalanx sclerosis.X-rays also establish the severity of disease progression.
Initial treatment includes analgesics and footwear modification to reduce joint movement (ie, orthoses, or stiff rocker bottom soled shoes). Corticosteroid injections can provide significant relief, even in individuals with severe pain.Sodium hyaluronate injection is a newer option. In a comparison between triamcinolone steroid injection and hyaluronate injection (N=37 patients; 40 total feet), both the steroid and hyaluronate injection provided better pain relief than baseline; gait pain was most improved in the hyaluronate group.
When conservative measures fail, surgical options include MTP arthrodesis, joint resurfacing, osteochondral autografting, MTP fusion, hemi-arthroplasty, and arthroplasty. Most provide some pain relief.,, Surgical repair of severe or chronic hallux rigidus may cause MTP joint fixation, which can be career-ending for some athletes and professional dancers. Joint-sparing surgical techniques include chilectomy (resection of hypertrophied bone or osteochondral surfaces along the articulation surface).
The hallucal sesamoids are 2 small bones underlying the first metatarsal in the flexor hallucis brevis (FHB) tendon. They increase mechanical advantage by acting as fulcrums for the FHB, absorbing weight-bearing forces, reducing friction, and elevating the first metatarsal head, which disperses forces to this area.,, Sesamoid injury, including acute or stress fracture, osteonecrosis, chondromalacia, soft-tissue inflammation, or compromise of the sesamoid complex, causes a pain syndrome called sesamoiditis.
Sesamoiditis results from excessive repetitive pressure or a single traumatic event involving the distal first metatarsal. Young athletes in sports requiring repetitive forceful connection between the ball of the foot and the ground, and especially ballet dancers, are most affected.Deformities that alter weight-bearing forces on the first MTP (eg, pes planus or cavus, hallux valgus or varus) increase risk. The most common manifestation is pain with weight bearing, with certain footwear exacerbating the pain.
Physical examination, when abnormal, reveals swelling and discoloration overlying the sesamoid. Direct tenderness over a sesamoid, or pain with resisted plantar flexion of the first MTP, is a sign of sesamoid pathology.
X-ray evaluation is important for suspected sesamoid pathology. Fractures, bipartite sesamoids, and osteonecrosis (characterized by radiolucency, sclerosis of fragments, and eventual fragmentation) can be the cause.It can be difficult to distinguish between a sesamoid fracture and a naturally bipartite sesamoid on x-ray results; MRI may be helpful in making this distinction. Injection of local anesthetic into the first MTP joint can be performed to rule out intra-articular pathology as the source of pain. Joint injection is not a standard part of the evaluation; whether corticosteroid injection is useful for treating sesamoiditis is unclear.
First-line intervention involves padding to offload the sesamoids. It may take up to 6 months with a less-intense training or activity regimen for complete symptom resolution.
If conservative treatment is ineffective, further diagnostic imaging options are MRI study, computed tomography scan, or technetium bone scan.These clarify the specific injury prior to surgical intervention. For individuals with intractable pain for more than 6 months after initial treatment, surgery should be considered. Sesamoidectomy can be performed on both sesamoid bones, although partial (versus total) resection is preferred to prevent great toe misalignment due to disruption of the FHB mechanics.
Lesser Toe Metatarsalgia
Lesser (second through fifth) toe metatarsalgia results from a variety of factors, including trauma; tight-fitting shoes; and inflammatory arthropathies such as gout, rheumatoid arthritis, and systemic lupus erythematosus. In athletes, symptoms are more often related to MTP instability, stress fractures, or interdigital neuromas.
Metatarsophalangeal instability, especially of the second MTP joint, is a common cause of lesser toe metatarsalgia in athletes. Risk factors include elongated second toe and hallux valgus. In patients with diabetes and motor neuropathy, strength inequality between muscle groups in the feet can lead to imbalance and instability. Patients may report a sensation of “walking on a rock.” Examination reveals plantar tenderness of the affected metatarsal and a positive drawer test result, indicated by pain and possible MTP joint subluxation or dislocation.X-rays of the foot are not helpful for diagnosis.
Initial treatment includes buddy taping of adjacent toes and plantar padding to offload stress. Without treatment, surrounding ligaments and the plantar plate are overstretched, which can result in a chronic condition requiring surgery.
Metatarsal Shaft Stress Fractures
Individuals with fractures present with gradual onset of pain with activity, which progresses to worsening pain and frank fracture. Point tenderness is typically noted over the fracture site. Diagnosis is usually made by history and physical examination. X-rays might not reveal stress fractures until 2 to 6 weeks after injury, if ever. An MRI study and technetium bone scan might be needed for definitive diagnosis.
Treat by avoiding activities that exacerbate the condition for 4 to 8 weeks. Crutches can be used for a short time if walking causes pain, and immobilization for 6 weeks might be necessary. Activity is increased gradually after symptom resolution, guided by pain level. When exercise is started prematurely or increased too rapidly, recurrence is possible.The role of orthoses in stress-fracture prevention is being studied. Preliminary studies show decreased second-metatarsal-strain severity with custom neutral-plaster-cast orthoses during simulated walking using cadaveric specimens.
Morton neuroma results from enlargement and entrapment of the third plantar intermetatarsal nerve from repetitive microtrauma and resulting reparative fibrosis.The etiology is unclear. Contributing factors include poorly fitting footwear and foot deformities such as high-arched foot, flatfoot, bunion, and hammer toe. Women ages 45 to 50 years are most typically affected. Symptoms typically are unilateral and exacerbated by weight bearing and driving and include sharp or burning localized pain, paresthesias or dysesthesias of the second or third webspace, and toe cramping. Nocturnal pain is typical. Removing uncomfortable footwear and massaging the foot can improve symptoms.
On physical examination, the foot can appear normal or have slight divergence of the third and fourth digits, which is exaggerated with weight bearing. Tenderness in the plantar forefoot is best elicited with plantar pressure between metatarsal heads. A lateral foot squeeze, which mimics tight footwear, might reproduce symptoms more consistently. The Mulder test is the most sensitive physical examination maneuver. It involves lateral forefoot compression with 1 hand, alternated with compression of the intermetatarsal space between the thumb and forefinger of the examiner’s opposite hand. The test result is positive if symptoms are reproduced or a palpable or audible click is elicited.,
Pain relief after injection of local anesthetic or common digital nerve block confirms the diagnosis. Proper placement of a second webspace injection, for example, is confirmed by numbness on the lateral surface of the second toe and medial surface of the third toe. If the patient has numbness in the expected distribution without pain relief, alternative diagnoses such as arthritis, synovitis, or stress fracture should be explored.
Although a diagnosis is often made clinically, imaging studies can be helpful, especially if surgery is planned.On ultrasound, Morton neuromas are seen proximal to the metatarsal heads and have variable shapes. MRI reveals a small hypointense lesion on T1-weighted images (slightly hyperintense to skeletal muscle) and an intermediate signal lesion on T2-weighted images.
Conservative initial treatment includes footwear modification, analgesics, and Achilles tendon stretching. Corticosteroid injection offers significant short-term pain relief.Multiple corticosteroid injections increase the risk of skin complications at the time of surgery, although this is not a surgical contraindication.
Surgical intervention is considered when conservative measures fail. Techniques include simple neurectomy, neurectomy with intermuscular transposition of the nerve stump, transverse metatarsal ligament release with neurolysis, and endoscopic ligament decompression.Persistent numbness in the nerve distribution is a potential surgical complication.
Chemical neurolysis via alcohol injection is another treatment option. One study of sonographically confirmed Morton neuroma showed 84 of 100 patients were pain-free between 7 and 19 months following injection of 0.1 mL of 100% ethyl alcohol diluted in 0.4 mL of 0.25% bupivacaine under ultrasound guidance.
Case 5, cont’d. Erna returns for follow-up 8 weeks after initiating a trial of padding around the sesamoid bones and wearing more flat, broad-based shoes. She reports that the pain is much improved and that she will now be avoiding high-heeled shoes. She is advised to follow up for any change in condition.
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