Partial regression of nevus spilus and halo nevus.

Abstract

Nevus spilus consists of melanocytic nevi that stand on a hypermelanic stain. Both the nevi and the dark stain may be absent at birth, but they tend to become more visible with time, the stain becoming darker and the nevi becoming more numerous. In our case after an initial increase of its evidence nevus spilus at the age of ten began to decrease in visibility due to a decreased pigmentation of the underlying stain and a clear regression of melanocytic nevi. As this regression occurred at the same time of autoimmune regression of common melanocytic nevi we hypothesized that even the regression of nevus spilus was autoimmune. The autoimmune inflammation of halo nevus is extremely variable going from the maximum clinical evidence to its complete absence not only clinical but also histological (1, 2).