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Pustules

Definition

Pustules are small, inflamed, pus-filled, blister-like sores (lesions) on the skin surface.

Considerations

Pustules are common in acne and folliculitis (inflammation of the hair follicle). They may occur anywhere on the body, but are most commonly seen in these areas:

  • Back
  • Face
  • Over the breastbone
  • Shoulders
  • Sweaty areas, such as the groin or armpit

Pustules may be a sign of an infection. In some cases, they are non-infectious and associated with inflammation in the skin or medicines. They should be checked by a health care provider and may need to be tested (cultured) for bacteria or fungus.

Gallery

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.
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.
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.
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.

References

Dinulos JGH. Principles of diagnosis and anatomy. In: Dinulos JGH, ed. Habif's Clinical Dermatology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 1.

Marks JG, Miller JJ. Pustules. In: Marks JG, Miller JJ, eds. Lookingbill and Marks' Principles of Dermatology. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 12.

Last reviewed November 4, 2020 by Elika Hoss, MD, Senior Associate Consultant, Mayo Clinic, Scottsdale, AZ. 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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