Definition:

Darier disease is a skin disorder with keratotic papules and plaques in seborrheic areas (central trunk, flexures, scalp, and forehead) and nail abnormalities. The disease usually starts at puberty and characterized by loss of cell-to-cell adhesion and abnormal keratinization. Darier disease is caused by mutations in ATP2A2, the gene encoding a sarco/endoplasmic reticulum Ca2+-ATPase. Because of some similarities in their etiopathology, Hailey-Hailey disease [DS:H00844] is often discussed together with Darier disease. Both diseases are autosomal dominantly inherited genodermatosis and are caused by abnormal epidermal calcium homeostasis.