Acne urticata associated with chronic myelogenous leukemia.

A 56-year-old woman presented with a 6-month history of acne urticata, an intensely pruritic papulopustular eruption. Skin biopsy was nondiagnostic. Touch preparations of individual lesions were remarkable for numerous eosinophils. Peripheral blood count, bone marrow examination, and Philadelphia chromosome positivity confirmed a diagnosis of chronic myelogenous leukemia. A serum histamine level was markedly elevated. Treatment with hydroxyurea and antihistamines led to resolution of the skin eruption and improvement of the pruritus.