Acquired dermal macular hyperpigmentation: a unified spectrum of dermal pigmentary dermatoses.

Acquired dermal macular hyperpigmentation (ADMH) encompasses a group of dermal pigmentary disorders (lichen planus pigmentosus, erythema dyschromicum perstans and Riehl melanosis/pigmented cosmetic dermatitis) that present with insidious-onset grey-to-brown macules and patches due to dermal melanin deposition. Traditionally regarded as distinct entities, these disorders share overlapping clinical, dermoscopic and histopathological features, leading to the adoption of ADMH as a unifying term. In this focused review, we discuss the pathogenesis and clinical features of ADMH, as well as diagnostic methods and treatment options for this spectrum of disorders.