Hypopigmentation of the skin Hypomelanotic macule 2009-01-31T12:16:52Z Hypomelanotic macules ("ash leaf spots") are white or lighter patches of skin that may appear anywhere on the body and are caused by a lack of melanin. White ash leaf-shaped macules are considered to be characteristic of tuberous sclerosis. HP:0009719 Hypomelanotic macules UMLS:C4024220 While hypopigmentation is a general term that refers to any form of decreased or absent skin pigmentation, hypomelanosis more specifically refers to a reduction of epidermal melanin. Hypopigmented macule