Anthralin: An anthracene derivative that disrupts MITOCHONDRIA function and structure and is used for the treatment of DERMATOSES, especially PSORIASIS. It may cause FOLLICULITIS.Alopecia Areata: Loss of scalp and body hair involving microscopically inflammatory patchy areas.Administration, Topical: The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.Psoriasis: A common genetically determined, chronic, inflammatory skin disease characterized by rounded erythematous, dry, scaling patches. The lesions have a predilection for nails, scalp, genitalia, extensor surfaces, and the lumbosacral region. Accelerated epidermopoiesis is considered to be the fundamental pathologic feature in psoriasis.