Impetigo is a common skin infection.
Impetigo is caused by streptococcus (strep) or staphylococcus (staph) bacteria. Methicillin-resistant staph aureus (MRSA) is becoming a common cause.
The skin normally has many types of bacteria on it, but intact skin is an effective barrier that keeps bacteria from entering and growing in the body. When there is a break in the skin, bacteria can enter the body and grow there, causing inflammation and infection. Breaks in the skin may occur with:
Impetigo may also occur on skin where there is no visible break.
It is most common in children, particularly those in unhealthy living conditions.
In adults, it may follow other skin disorders or a recent upper respiratory infection such as a cold or other virus. It is similar to cellulitis, but it only involves the top layers of the skin.
Impetigo is contagious, meaning it can spread to others. You can catch this infection if the fluid that oozes from the blisters touches an open area on your skin.
Habif TP. Bacterial infections. In: Habif TP, ed. Clinical Dermatology. 5th ed. St. Louis, Mo: Mosby Elsevier; 2009:chap 9.
Pasternack MS, Swartz MN. Cellulitis, necrotizing fasciitis, and subcutaneous tissue infections. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 90.
© 2011 University of Maryland Medical Center (UMMC). All rights reserved.
UMMC is a member of the University of Maryland Medical System,
22 S. Greene Street, Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885