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

Acquired Dermal Macular Hyperpigmentation (ADMH) encompasses a group of pigmentary disorders-lichen planus pigmentosus, erythema dyschromicum perstans, and Riehl's 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 conditions 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, clinical features, diagnostic methods and therapeutic options of ADMH.