Rash can signal any number of disorders, from the relatively minor to the life-threatening. For a 62-year-old woman, an unrelenting skin complaint proved to be evidence of an unusual disease. She presented with a 2.5-year history of an intermittent pruritic rash in her underarms and gluteal cleft and on her groin and legs. It had become persistent in the last 3 months and was refractory to treatment with high-potency topical steroids, topical antifungal agents, and topical antibiotics prescribed by her primary care providers.

She had been diagnosed with diabetes mellitus 5 months prior to our evaluation. In addition, she described a 20-pound weight loss and associated fatigue. Over the preceding 3 months, the patient had also developed new-onset alopecia. Physical examination revealed widespread, circumscribed, bilateral and symmetric erythematous eroded plaques with scale, which were located primarily in the axilla and gluteal cleft and on the trunk, groin, and upper legs (Figure, A and B). Erythematous scaly plaques were also noted in continuity with the oral labial commissures, consistent with angular cheilitis (Figure, C).

Examination of the mouth demonstrated swelling and redness of the tongue consistent with glossitis.