PD Wilson, RM Lavker, AM Kligman
DOI: 10.2340/0001555562301306

Clinical and morphologic studies were made of 20 cases of guttate hypomelanosis. The sharply demarcated hypopigmented macules were present on both covered and exposed sites, excluding sunlight exposure as a cause. Skin surface replicas and biopsies showed no evidence of post-traumatic or post-inflammatory scarring. The stratum corneum had fewer cell layers, but no abnormalities of keratinization were observed. Light and electron-microscopic and histochemical studies showed only reduced numbers of hypoactive melanocytes. In no case were melanocytes completely absent, excluding vitiligo. Guttate hypomelanosis is a common disorder of unknown origin. The evidence indicates an age-related somatic mutation of melanocytes.