Acne and related disorders.

Acne vulgaris is the clinical expression of inflammation of the pilosebaceous unit. Factors known to predispose to the development of acne include increased sebum, which is acted on by Propionobacterium acnes to generate inflammatory substances, and retention hyperkeratosis, which causes obstruction of the sebaceous follicle. Therapeutic modalities for acne include topical and systemic antibiotics, comedolytic agents (such as benzoyl peroxide and topical retinoids) and systemic retinoids. Acne scars may be treated surgically using procedures such as dermabrasion and dermal injections of bovine collagen or simple scar excision, scar punch elevation, or punch grafting.