blackhead, yellowish or blackish plug of material accumulated in the duct of a sebaceous gland. The material consists of keratin (horny cells of the epidermis) and modified sebum (oily secretions of the sebaceous gland). Blackheads are the primary lesions in acne . Treatment is the same as for acne, with frequent cleansing of the skin followed by the application of astringent solutions. Plugs should be extracted only by a physician, since damage to the surrounding tissues occasioned by squeezing often leads to scarring.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Pathology