Regressing nevoid nail melanosis in childhood.

The natural course of nail pigmentation was documented in 4 Japanese children. Although initial progression of melanosis concerning size and degree of pigmentation was noted, all cases showed a tendency to fade during the follow-up period. The published cases of nevoid nail melanosis in childhood were reviewed, and we concluded that they were essentially benign. However, should there be any suspicion of malignant changes, punch biopsy is indicated for medico-legal reasons. Management of growing pigmented nail streaks in childhood is one of the most difficult and delicate problems facing dermatologists, as they can be precursors of malignant melanoma. There is a condition of the nail known as longitudinal melanonychia or naevus striae unguis, possibly of nevoid nature. Prevalence rates of nevoid diseases showing pigmentation of the skin vary depending on the ethnic origin. In order to understand the natural course of nail area pigmentation in childhood, we have followed 4 Japanese children with such a condition. We report our observations and review the literature.