A common skin condition involving blockage and/or inflammation of hair follicles and associated sebaceous glands, most often affecting the face, upper back, and chest. Acne may present as inflammatory lesions (e.g., papules, pustules, cysts, nodules), noninflammatory lesions (e.g., open or closed comedones known as blackheads and whiteheads), or a mixture of both.

Synonyms: acne vulgaris