Tinea versicolor mimicking pityriasis rubra pilaris.

Tinea versicolor is a common noninvasive cutaneous fungal disease. We recount a case of tinea versicolor that mimicked type I (classic adult) pityriasis rubra pilaris. A 54-year-old white man reported a 20-year history of a recurrent pruritic eruption that had marginally improved with use of selenium sulfide shampoo and treatment with oral antihistamines. Results of a skin examination revealed erythematous plaques; islands of spared skin; and follicular erythematous keratotic papules on the trunk, shoulders, and upper arms. A lesion was scraped to obtain skin scales for potassium hydroxide staining. Examination of the stained samples revealed the characteristic "spaghetti and meatballs," confirming the diagnosis.