Congenital nevus before and after onset of halo.

Abstract

A 1-year-old boy, born full term normal
delivery, was first observed due to a small nevus present
since birth on his left knee. Physical examination
(Fig. 1) showed a melanocytic nevu, about 1 cm in size,
deeply pigmented with slightly irregular outline. Dermoscopy
(Fig. 2) showed a globular pattern with brown
and some bluish globules.
After five years we reviewed the child before the
summer for the appearance of a vitiligo halo around
the nevus (Fig. 3). His mother reported to be affected
by autoimmune thyroiditis. At the end of summer (Fig.
4) the halo expanded and took a sharp outline. Dermoscopy
(Fig. 5, 6) showed on the center (C, residual
nevus Fig. 6) irregular globules in regression without
overt signs of inflammation, in the context of the halo
(A in Fig. 5) blackish points and filaments up to the
limit with the healthy skin (S Fig. 5).