Hypermelanoses of the newborn and of the infant.

This article discusses hypermelanoses present at birth or appearing in the first months of life. They may be transient or permanent, localized - as in café-au-lait spots - or segmental, or more rarely, complex or generalized. In most pigmentary diseases, physical examination, including Wood's lamp examination and a detailed history, is usually sufficient. Time of onset, distribution pattern, and associated clinical and sometimes histopathologic findings are helpful in differentiating these disorders. Recently, molecular diagnosis has become available for some rare entities, such as hereditary symmetrical dyschromatoses, but the bulk of nevoid lesions are not understood at the molecular level.