ABSTRACT
Hypopigmentation disorders may present with different phenotypes. A basic step in the diagnostic approach to the patient with hypopigmentation is to classify whether the hypopigmentation/depigmentation is congenital (appears at birth) or presents later in life. Further subclassification of hypopigmentation follows, depending on the distribution of hypopigmentation as widespread or circumscribed/localized. Disorders of congenital hypopigmentation/depigmentation include diseases due to genetic defects in the pigmentation pathway such as albinism, piebaldism, Waardenburg syndrome, Hermansky-Pudlak syndrome, and Chediak-Higashi syndrome. Hypopigmented macules of tuberous sclerosis complex and nevus depigmentosus may also be present at birth. Disorders with hypopigmentation that presents later in life include vitiligo, incontinentia pigmenti, and acquired diseases. A physical examination and a thorough medical history for a known history of other inflammatory skin diseases, infectious or parasitic skin diseases that may present with hypopigmentation, or the use of topical agents or systemic drugs should be investigated for a possible cause of hypopigmentation.
