What is nevus depigmentosus?

Nevus depigmentosus consists of single or multiple hypopigmented macules or patches that grow proportionally with the patient. The trunk is the most commonly affected body area. However, nevus depigmentosus has been reported to occur on the extremities, buttocks, and face, and may be localized, segmental, or, less often, systematized. Most lesions present by age 3 years with the remainder (about 7%) presenting later in childhood. Lesion morphology varies from circumscribed irregular, oval, or round macules or patches to a unilateral band or streak with a “splashed paint” appearance arranged along one or more Blaschko line. Lesional skin has normal melanocyte number but reduced numbers of melanosomes in melanocytes and surrounding keratinocytes. The etiopathogenesis has not been fully established.