Acquired dermal macular hyperpigmentation (ADMH) is a group of diseases clinically characterized by grayish-black macules and patches, with pigment predominantly deposited in the dermis. ADMH includes Riehl's melanosis, lichen planus pigmentosus, and erythema dyschromicum perstans/ashy dermatosis. In light of the remarkable similarities in both morphological and histopathological characteristics among this group of diseases, the academic community has recently proposed the new nosological term "acquired dermal macular hyperpigmentation" to achieve integration and unified classification of these related disorders. This review comprehensively elaborates on advances in the diagnosis and treatment of ADMH, including clinical manifestations, dermoscopic findings, pathological characteristics, and treatment progress.

Acquired dermal macular hyperpigmentation (ADMH) is a group of diseases clinically characterized by grayish-black macules and patches, with pigment predominantly deposited in the dermis. ADMH includes Riehl's melanosis, lichen planus pigmentosus, and erythema dyschromicum perstans/ashy dermatosis. In light of the remarkable similarities in both morphological and histopathological characteristics among this group of diseases, the academic community has recently proposed the new nosological term "acquired dermal macular hyperpigmentation" to achieve integration and unified classification of these related disorders. This review comprehensively elaborates on advances in the diagnosis and treatment of ADMH, including clinical manifestations, dermoscopic findings, pathological characteristics, and treatment progress.