Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Causes
By Mayo Clinic staffTwo types of bacteria cause impetigo — Staphylococcus aureus (staph), which is most common, and Streptococcus pyogenes (strep). Both types of bacteria can live harmlessly on your skin until they enter through a cut or other wound and cause an infection.
In adults, impetigo is usually the result of injury to the skin — often by another dermatological condition such as dermatitis. Children are commonly infected through a cut, scrape or insect bite, but they can also develop impetigo without having any notable damage to the skin.
You're exposed to the bacteria that cause impetigo when you come into contact with the sores of someone who's infected or with items they've touched, such as clothing, bed linen, towels and even toys. Once you're infected, you can easily spread the infection to others.
Staph bacteria produce a toxin that causes impetigo to spread to nearby skin. The toxin attacks a protein that helps bind skin cells together. Once this protein is damaged, bacteria can spread quickly.
- Habif, TP. Bacterial infections. In: Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 4th ed. Philadelphia, Pa.: Mosby, Inc; 2004. http://www.mdconsult.com/das/book/body/103909824-2/0/1195/53.html?tocnode=51440785&fromURL=53.html#4-u1.0-B0-323-01319-8..50011-X_938. Accessed Aug. 11, 2008.
- Morelli JG. Cutaneous bacterial infections. In: Kliegman RM, et al. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa.: Saunders Elsevier; 2007. http://www.mdconsult.com/das/book/body/103909824-3/743716949/1608/1552.html#4-u1.0-B978-1-4160-2450-7..50666-6--cesec5_12130. Accessed Aug. 11, 2008.
- Cole C, et al. Diagnosis and treatment of impetigo. American Family Physician. 2007;75(6):859-864, 868.
- Lopez FA, et al. Skin and soft tissue infections. Infectious Disease Clinics of North America. 2006;20(4):759-772.
- Community-associated MRSA information for the public. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dhqp/ar_mrsa_ca_public.html. Accessed Aug. 11, 2008
- Baddour LM, et al. Impetigo. http://www.uptodate.com/home/index.html. Accessed Aug. 11, 2008.
