A 61-year-old woman presented with a recurrent right groin abscess. Two years earlier, she had presented to the emergency department with proximal right thigh pain and swelling of one week’s duration. She was presumed to have a hematoma or abscess and was treated with oxycodone/acetaminophen and amoxicillin/clavulanate. She was subsequently examined and treated every few months for a presumed abscess. She underwent five incision and drainage procedures, surgical wound debridement, a wide excision of the abscess, treatment with antibiotics, wound care, and imaging studies. Despite short-term improvement, the abscess did not fully heal and symptoms recurred.

The patient’s medical history included fibromyalgia and stress urinary incontinence. Her surgical history included total hysterectomy, transobturator and retropubic midurethral sling procedure, and cholecystectomy. She had a 40-pack-year smoking history.

On physical examination, the area was painful to palpation, and bloody fluid was draining from the abscess (Figure 1). Mild erythema was present around the abscess, but no fluctuance or warmth was noted. The right hip had full range of motion.

Question

Based on the patient’s history and physical examination findings, which one of the following is the most likely diagnosis?

• A. Enterocutaneous fistula.

• B. Foreign body.

• C. Hidradenitis suppurativa.

• D. Methicillin-resistant Staphylococcus aureus (MRSA) infection.

• E. Pyoderma gangrenosum.

Discussion

The answer is B: foreign body. The patient’s recurrent groin abscess was the result of an infection originating from the mesh placed during the transobturator midurethral sling procedure. The key to diagnosis was the patient’s surgical history to treat stress urinary incontinence. Stress incontinence affects up to 50% of women older than 40 years.¹ Surgery is the most common treatment option.² Three midurethral mesh sling procedures are available to prevent leaking related to stress urinary incontinence: retropubic, transobturator, and single-incision or “mini sling.”²

The transobturator approach is associated with postoperative groin pain in approximately 12% to 16% of patients, which should subside within six weeks of the procedure. A release or removal may be needed.³ Other complications from midurethral sling surgeries include exposure (retropubic = up to 13%; transobturator = up to 10%; mini sling = up to 19%) and wound infection (retropubic = up to 13%; transobturator = up to 2%; mini sling = up to 1%).⁴ Although the risk of complications from a midurethral sling is relatively low overall, the placement of mesh is a potential nidus for infection and should be considered in patients with a history of mesh placement who are experiencing pain in relevant areas. Approximately one-half of women with urinary incontinence do not readily provide clinicians with information about the condition or treatments they have received. Unless patients are specifically asked, an essential component to the diagnostic history can be missed in women with recurrent groin abscess.⁵

An enterocutaneous fistula can be a complication of inflammatory bowel disease and occurs in approximately one-third of people with Crohn disease. The fistulas can be internal (bowel to bladder) or enterocutaneous (abdominal wall or perineum). Recurrent drainage may occur, possibly with fecal or urinary findings in excretions.⁶

Hidradenitis suppurativa is a common disorder of apocrine gland–bearing follicular epithelium in which hyper-keratosis leads to occlusion and subsequent follicular rupture. This can cause potential inflammation and secondary infection. The condition is characterized by tender papules or deep nodules, usually in the axilla, perineum, or groin, that can coalesce into a large, painful inflammatory abscess. Sinus tracts, puckered skin, pigment changes, or scarring may occur.⁶

MRSA skin infections typically present as red, swollen, painful, warm sores with purulent or serous drainage. A culture sample can be taken from an open sore or blood. MRSA infections are common in people with weak immune systems and those who are in close contact with a person who has a MRSA infection.

Pyoderma gangrenosum is a rare noninfectious neutrophilic dermatosis manifesting as pustules that rapidly progress into painful ulcers of various depths and sizes, usually on the legs. In about one-half of cases, the condition is associated with underlying systemic disease, most commonly inflammatory bowel, rheumatic, or hematologic disease.⁶