Case report. Pityriasis versicolor mimicking Pityriasis rotunda

Pityriasis versicolor is a common dermatomycosis, occurring throughout the world, characterized by irregular, slightly scaly patches, varying in color from red/light brown to white. Pityriasis rotunda, on the other hand, is an uncommon disease, reported in specific ethnic groups, and characterized by perfectly round or oval patches of varying color, with a scaly surface. The histologic pattern is that of ichthyosis vulgaris. We report here the case of a male patient, aged 31, from Sardinia (Italy), affected by Pityriasis versicolor mimicking Pityriasis rotunda. Mycological examination allowed us to formulate the correct diagnosis, and ensuing treatment with antifungal drugs was entirely successful. The authors, while pointing out the rarity of this case, stress the possibility that Pityriasis versicolor mimics Pityriasis rotunda and vice-versa, especially in those countries in which the two diseases are endemic. More widespread recourse to microscopic examination can help avoid the risk of mistaken diagnosis and consequent incorrect treatment.