Mastocytosis is a group of disorders characterized by the accumulation of mast cells in different tissues and organs. The skin is the most frequently involved organ (90% of cases) where mastocytosis may show a heterogenic clinical expression. Anetodermic lesions are an unusual clinical presentation of mastocytosis. We report a case of anetodermic mastocytosis in a 26-year-old man, with sparse lesions and a benign course. PUVA therapy obtained excellent results in this case. Darier's sign should be investigated in patients with anetodermic lesions of unclear origin in order to exclude cutaneous mastocytosis.