What is impetigo?

Impetigo is a bacterial skin infection. It causes red sores that can break open, ooze fluid, and develop a yellow-brown crust. These sores can occur anywhere on the body but most often appear around the mouth and nose.

See an illustration of impetigo.

Impetigo is one of the most common skin infections in children. It can occur in adults but is seen far more often in children. Impetigo is contagious and can be spread to others through close contact or by sharing towels, sheets, clothing, toys, or other items. Scratching can also spread the sores to other parts of the body.

Antibiotic ointment that is applied directly to the infected areas of skin usually cures impetigo. Sometimes antibiotic pills are needed.

What causes impetigo?

Impetigo is caused by one of two kinds of bacteria-strep (streptococcus) or staph (staphylococcus). Often these bacteria enter the body when the skin has already been irritated or injured because of other skin problems such as eczema, poison ivy, insect bites, chickenpox, burns, or cuts. Children may get impetigo after they have had a cold or allergies that have made the skin under the nose raw. However, impetigo can also develop in completely healthy skin.

How can impetigo be prevented?

If you know someone who has impetigo, try to avoid close contact with that person until his or her infection has gone away. You should also avoid sharing towels, pillows, sheets, clothes, toys, or other items with an infected person. If possible, wash any items that may have been shared in hot water before you use them again.

If you or your child has impetigo, scratching the sores can spread the infection to other areas of your body and to other people. Keeping the sores covered can help you or your child resist scratching them. Washing your or your child's hands with antibacterial soap can also prevent spreading the infection.

If your child has a cut or insect bite, covering it with antibiotic ointment can help prevent impetigo.

What are the symptoms of impetigo?

You may have impetigo if you have sores:

• On your skin, especially around the nose or mouth. The sores begin as small red spots, then change to blisters that eventually break open. The sores are generally not painful, but they may be itchy.
• That ooze fluid and look crusty. Sores often look like they have been coated with honey or brown sugar.
• That increase in size and number. Sores may be as small as a pimple or as large as a coin.

How is impetigo diagnosed?

Your doctor can usually diagnose impetigo just by looking at your or your child’s skin. Sometimes your doctor will gently remove a small piece of a sore to send to a lab in order to identify the bacteria. If you or your child have other signs of illness, your doctor may order blood or urine tests.