Photo Quiz

Digital Clues


Am Fam Physician. 2018 Apr 1;97(7):465-466.

A 90-year-old man presented with increasing fatigue over the previous two to three months. His daughter reported that he was fatigued with simple activities of daily living. The patient had not been seen by a physician for approximately 10 years. He reported a decreased appetite and mild dyspnea on exertion, but no chest pain. He had no symptoms of depressed mood. He had a history of poststreptococcal glomerulonephritis when he was a teenager, but no other medical conditions.

On physical examination, his blood pressure and pulse while sitting were normal. He had pallor and skin turgor appropriate for an older person. Cardiac and pulmonary examination findings were normal. He had no cyanosis in the extremities; however, his fingernails were deformed (Figures 1 and 2).

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

A. Iron deficiency anemia.

B. Onychomycosis.

C. Psoriasis.

D. Squamous cell carcinoma.


The answer is A: iron deficiency anemia. Spoon-shaped nails (koilonychia) are often indicative of a systemic illness. Iron deficiency anemia is the most common cause of isolated koilonychia.1 Patients with iron overload, as in hemochromatosis, may also develop koilonychia.2 A complete blood count and ferritin level should be ordered for patients with koilonychia to rule out iron abnormalities. Koilonychia can also be caused by occupational exposure to solvents or by chronic trauma,3 and it is a normal physiologic finding in infants.2 Other common signs and symptoms of iron deficiency anemia include weakness and fatigue, pale skin, chest pain or palpitations, dizziness, and pica (craving for ice or dirt).

Onychomycosis, a fungal nail infection, commonly affects the toenails but can also affect the fingernails. Fungi from the skin invades the nail bed, creating the appearance of o

Author disclosure: No relevant financial affiliations.

Address correspondence to Rob Danoff, DO, MS, at Reprints are not available from the authors.


show all references

1. Killip S, Bennett JM, Chambers MD. Iron deficiency anemia [published correction appears in Am Fam Physician. 2008;78(8):914]. Am Fam Physician. 2007;75(5):671–678....

2. Tully AS, Trayes KP, Studdiford JS. Evaluation of nail abnormalities. Am Fam Physician. 2012;85(8):779–787.

3. Onychomycosis. In: Usatine RP. The Color Atlas of Family Medicine. New York, NY: McGraw-Hill; 2013:829–833.

4. Armstrong AW. Nail psoriasis. Updated August 15, 2017. UpToDate. [subscription required]. Accessed May 16, 2017.

This series is coordinated by John E. Delzell Jr., MD, MSPH, Associate Medical Editor.

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