Photo Rounds

Woman with rash in groin

A 35-year-old woman presented to her family physician with an itchy rash in her groin that she’d had for 3 months. She was otherwise in good health.

What’s your diagnosis?


The family physician (FP) suspected that the patient had tinea cruris, but hadn’t ever seen it spread so far from the inguinal area. The rash had central clearing, which is typical of tinea corporis, but is not seen as often with tinea cruris. The FP performed a potassium hydroxide (KOH) preparation, which was positive for branching septate hyphae. (See video on how to perform a KOH preparation here.)

The FP discussed the treatment options, which consisted of topical antifungal medicine vs oral antifungal medicine. The patient was willing to try the topical terbinafine and return for a follow-up appointment in a month. The FP told the patient that he would give her oral terbinafine if the topical terbinafine didn’t work. One month later, the skin had cleared and the patient was happy with the results.

Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Usatine R, Smith M. Tinea cruris. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:795-798.

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