Familial white lentiginosis (FWL) is a rare acquired disorder of macular hypopigmentation. The characteristic lesions (guttate white macules typically distributed on the trunk, neck, and extensor surfaces of the upper arms) present at birth or during early childhood and predominantly affect females with skin phototypes IV-V. The lesions are asymptomatic but may rapidly spread from the time they first appear and do not regress.

With only a few cases reported since its initial description, little is known regarding the pathophysiologic basis for FWL. Nevertheless, the familial nature of the disorder, with a strong predilection for females in consecutive generations, is evident in the described cases. This pattern suggests autosomal dominant or X-linked inheritance and points to a genetic component of the disorder's origin.

FWL is a benign chronic condition and does not appear to be associated with other underlying disorders.