Will the Real Tinea Please Stand Up …
3. For two months, an 8-year-old girl has had a mildly tender and markedly pruritic rash on her right lower leg. Physical exam reveals concentric annular lesions on the affected leg. The central areas demonstrate a bruised appearance that does not resolve with diascopy.
Image courtesy of Robert Brodell, MD; reprinted from The Journal of Family Practice (2014;63:395-396).
Diagnosis: Tinea corporis was confirmed by the results of a potassium hydroxide (KOH) preparation showing septate hyphae. A periodic acid-Schiff (PAS) stain performed on the previous biopsy specimen revealed septate hyphae in the stratum corneum that were not apparent on the original hematoxylin and eosin (H&E) stained sections.
Dermatophyte infections of the skin are known as tinea corporis or “ringworm.” Ringworm fungi belong to 3 genera, Microsporum, Trichophyton, and Epidermophyton. These infections occur at any age and are more common in warmer climates.1 The classic lesion is an annular scaly patch, sometimes with the concentric rings, as seen in our patient. The bruising was almost certainly caused by rubbing and scratching.
1. Shrum JP, Millikan LE, Bataineh O. Superficial fungal infections in the tropics. Dermatol Clin. 1994;12:687-693.
For more information on this case, see “Young girl with lower leg rash.” J Fam Pract. 2014;63(7):395-396.
