Pityriasis versicolor a sede atipica: valutazioni epidemiologiche [Pityriasis versicolor in unusual sites: An epidemiological study]

Background. Pityriasis versicolor is a superficial mycosis due to Malassezia, a dimorphic lipophilic yeast. It frequently occurs on the chest, proximal upper extremities, neck and nape in adolescents and adults, and rarely on the face and forehead in children. Involvement of unusual sites is a rare but possible event. A retrospective study analyzing the data from the Mycology Laboratory of the Dermatology Department of the University of Catania aimed to evaluate the real incidence of pityriasis versicolor at unusual sites during the last four years is presented. Methods. Included in the study were all adults or children, either inpatients and outpatients, in whom a diagnosis of pityriasis versicolor had been confirmed by Wood lamp examination and by direct microscopy. Results. Between January 1997 and December 2000, 836 patients with pityriasis versicolor, with age ranging from 1 to 86 years (mean age: 11 years; M/F≅1), were identified. Forty of them (4.8%), 29 adults (11 M-18 F) and 11 children (6 M-5 F), presented with pityriasis versicolor lesions localized at unusual sites, such as face, extensor aspect of forearms and antecubital fossae, submammary regions and groins and popliteal fossae in adults, and trunk and upper arms in children. Conclusions. The occurrence of pityriasis versicolor in unusual sites is a relatively common event. In such cases, confirmation by adequate laboratory investigations is mandatory.