Atrophic pityriasis versicolor occurring in a patient with Sjögren's syndrome.

Pityriasis versicolor is one of the most frequent epidermal mycotic infections in the world, but its atrophic variant is rarely described. The aetiology of the atrophy is still unknown, and two main hypotheses have been formulated, one suggesting a correlation with long-term use of topical steroids and the other a delayed type hypersensitivity to epicutaneous antigens derived from components of the fungus. Atrophic pityriasis versicolor is a benign disease, but needs to be distinguished from other more severe skin diseases manifesting with cutaneous atrophy. The diagnosis can be easily confirmed by direct microscopic observation of the scales soaked in 15% potassium hydroxide, which reveals the typical 'spaghetti and meatball' appearance, or by a skin biopsy in doubtful cases. Here, we describe a case of extensive atrophic pityriasis versicolor occurring in a woman affected by Sjögren's syndrome which completely resolved after topical antifungal treatment.