Atypical maculopapular cutaneous mastocytosis showing a nevus spilus-like lesion.

A 13-year-old Korean girl presented with a 7-year history of a pruritic, light-brown patch containing multiple 0.2- to 0.5-cm brownish-to-reddish maculopapules on the left anterior chest. When her skin was rubbed, the lesion became itchy and red. Histopathologic evaluation demonstrated marked dense dermal infiltration of mast cells. We report a rare case of atypical maculopapular cutaneous mastocytosis with clinical features similar to those of nevus spilus.