Idiopathic guttate hypomelanosis

Idiopathic guttate hypomelanosis is usually associated with guttate hyperkeratosis, xerosis, and lentiginosis not related to the patient's age. Histologically, hypopigmented macules show remarkably decreased melanin, decreased DOPA-oxidase activity and a decreased number of melanosomes in the melanocytes with predominance of Stages I and II and small sizes. The epidermis is always atrophic. When scales are removed by scraping, hyperkeratotic lesions show, clinically and histologically, variable degrees of hypomelanosis; thus suggesting a relationship with the hypopigmented macules. These data suggest that idiopathic guttate hypomelanosis is the result of an early aging of the skin.