Segmental nevus depigmentosus: analysis of 20 patients.

Achromic nevus or nevus depigmentosus is a cutaneous abnormality consisting of a hypopigmented macular lesion which can present as circumscribed irregular, oval, or round or as a unilateral band or streak with a blocklike configuration or arranged along one or more Blaschko lines. When it is systematized, it is indistinguishable from hypomelanosis of Ito. Pigmentary anomalies along the lines of Blaschko can be associated with systemic features. For these reasons, 20 children, referred consecutively for evaluation of segmental, linear achromic nevus, were evaluated to define the incidence of associated abnormal systemic features. Extracutaneous abnormalities were present in 2 of 20 children (10%). The anomalies consisted of pes cavus ipsilateral to the hypopigmentation in one child and mental retardation, seizures, and hemihypertrophy in the second. This study confirms that achromic nevus, even when distributed along Blaschko lines, is commonly a benign lesion that is associated with systemic features in a small minority of cases.