Impetigo (im-peh-TIE-go) is a bacterial infection of the skin that is most common in young children. Doctors use antibiotics to treat impetigo. Antibiotics can also help protect others from getting sick.
Two Bacteria Can Cause Impetigo
Impetigo is a skin infection caused by one or both of the following bacteria: group A Streptococcus and Staphylococcus aureus. This page focuses on impetigo caused by group A Streptococcus (group A strep). In addition to impetigo, group A strep cause many other types of infections.
How Someone Gets Impetigo
When group A strep infects the skin, it causes sores. The bacteria can spread to others if someone touches those sores or comes into contact with fluid from the sores.
Signs and Symptoms
In general, impetigo is a mild infection that can occur anywhere on the body. It most often affects exposed skin, such as around the nose and mouth or on the arms or legs.
Symptoms include red, itchy sores that break open and leak a clear fluid or pus for a few days. Next, a crusty yellow or “honey-colored” scab forms over the sore, which then heals without leaving a scar.
It usually takes 10 days for sores to appear after someone is exposed to group A strep.
Young Children Are at Increased Risk
Anyone can get impetigo, but some factors increase someone’s risk of getting this infection.
- Age: Impetigo is most common in children 2 through 5 years old.
- Infections or injuries that break the skin: People with scabies infection are at increased risk for impetigo. Participating in activities where cuts or scrapes are common can also increase someone’s risk of impetigo.
- Close contact or crowding: Close contact with another person with impetigo is the most common risk factor for illness. For example, if someone has impetigo, it often spreads to other people in their household. Infectious illnesses also tend to spread wherever large groups of people gather. Crowded conditions — such as those in schools and daycare centers — can increase the spread of impetigo.
- Climate: Impetigo is more common in areas with hot, humid summers and mild winters (subtropics), or wet and dry seasons (tropics), but it can occur anywhere.
- Poor personal hygiene: Lack of proper handwashing, body washing, and facial cleanliness can increase someone’s risk of getting impetigo.
Doctors Diagnose Impetigo by How It Looks
Doctors typically diagnose impetigo by looking at the sores (physical examination). Lab tests are not needed.
Antibiotics Treat Impetigo
Impetigo is treated with antibiotics that are either rubbed onto the sores (topical antibiotics) or taken by mouth (oral antibiotics). A doctor might recommend a topical ointment, such as mupirocin or retapamulin, for only a few sores. Oral antibiotics can be used when there are more sores.
Serious Complications Are Very Rare
Very rarely, kidney problems (post-streptococcal glomerulonephritis) can be a complication of impetigo. If someone has this complication, it usually starts one to two weeks after the skin sores go away.
Protect Yourself and Others
People can get impetigo more than once. Having impetigo does not protect someone from getting it again in the future. While there is no vaccine to prevent impetigo, there are things people can do to protect themselves and others.
Keep sores caused by impetigo covered in order to help prevent spreading group A strep to others. If you have scabies, treating that infection will also help prevent impetigo.
Good wound care is the best way to prevent bacterial skin infections, including impetigo:
- Clean all minor cuts and injuries that break the skin (like blisters and scrapes) with soap and water.
- Clean and cover draining or open wounds with clean, dry bandages until they heal.
- See a doctor for puncture and other deep or serious wounds.
- If you have an open wound or active infection, avoid spending time in:
- Hot tubs
- Swimming pools
- Natural bodies of water (e.g., lakes, rivers, oceans)
Appropriate personal hygiene and frequent body and hair washing with soap and clean, running water is important to help prevent impetigo.
The best way to keep from getting or spreading group A strep is to wash your hands often. This is especially important after coughing or sneezing. To prevent group A strep infections, you should:
- Cover your mouth and nose with a tissue when you cough or sneeze.
- Put your used tissue in the waste basket.
- Cough or sneeze into your upper sleeve or elbow, not your hands, if you don’t have a tissue.
- Wash your hands often with soap and water for at least 20 seconds.
- Use an alcohol-based hand rub if soap and water are not available.
You should wash the clothes, linens, and towels of anyone who has impetigo every day. These items should not be shared with anyone else. After they have been washed, these items are safe for others to use.
People diagnosed with impetigo can return to work, school, or daycare if they:
- Have started antibiotic treatment
- Keep all sores on exposed skin covered
Use the prescription exactly as the doctor says to.
Once the sores heal, someone with impetigo is usually not able to spread the bacteria to others.