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Comedones

Definition

Comedones are small, flesh-colored, white, or dark bumps that give skin a rough texture. The bumps are caused by acne. They are found at the opening of skin pores. A solid core can often be seen in the middle of the small bump. Open comedones are blackheads and closed comedones are whiteheads.

Alternative Names

Skin bumps - acne-like; Acne-like skin bumps; Whiteheads; Blackheads

Gallery

Skin layers
The skin is the largest organ of the body. The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection. It protects the body from external factors such as bacteria, chemicals, and temperature. The skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells. Another important function of the skin is body temperature regulation. When the skin is exposed to a cold temperature, the blood vessels in the dermis constrict. This allows the blood which is warm, to bypass the skin. The skin then becomes the temperature of the cold it is exposed to. Body heat is conserved since the blood vessels are not diverting heat to the skin anymore. Among its many functions the skin is an incredible organ always protecting the body from external agents.
Blackheads (comedones)
Blackheads, or open comedones, are common in acne. Clogged hair follicles reflect light irregularly to produce this black hue.
Acne - close-up of pustular lesions
Acne lesions frequently contain pus. This close-up photograph shows small acne pustules with surrounding inflammation (erythema).
Acne - close-up of pustular lesions
Acne lesions frequently contain pus. This close-up photograph shows small acne pustules with surrounding inflammation (erythema).
Pustules - superficial on the arm
An infection of the topmost layers of the skin, especially one caused by staphylococci, may produce pustules, which look like small blisters containing a thick, yellowish material.
Acne - close-up of pustular lesions
Acne lesions frequently contain pus. This close-up photograph shows small acne pustules with surrounding inflammation (erythema).
Acne - close-up of pustular lesions
Acne lesions frequently contain pus. This close-up photograph shows small acne pustules with surrounding inflammation (erythema).
Acne - close-up of pustular lesions
Acne lesions frequently contain pus. This close-up photograph shows small acne pustules with surrounding inflammation (erythema).

References

Dinulos JGH. Acne, rosacea, and related disorders. In: Dinulos JGH, ed. Habif's Clinical Dermatology: A Color Guide in Diagnosis and Therapy. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 7.

James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Acne. In: James WD, Elston DM, Treat JR, Rosenbach, MA, Neuhaus IM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 13.

Last reviewed October 10, 2020 by Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

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