Impetigo is a skin infection caused by bacteria. It is usually caused by staphylococcal (staph) bacteria, but it can also be caused by streptococcal (strep) bacteria. It is most common in children between the ages of two and six. It usually starts when bacteria get into a break in the skin, such as a cut, scratch, or insect bite.

Symptoms start with red or pimple-like sores surrounded by red skin. These sores can be anywhere, but usually they occur on your face, arms and legs. The sores fill with pus, then break open after a few days and form a thick crust. They are often itchy, but scratching them can spread the sores.

Impetigo can spread by contact with sores or nasal discharge from an infected person. You can treat impetigo with antibiotics.

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.

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.

Two types of bacteria found on our skin cause impetigo: Staphylococcus aureus and Streptococcus pyogenes (which also causes strep throat). Most of us go about our lives carrying around these bacteria without a problem, Smith says. But then a minor cut, scrape or insect bite allows the bacteria to cause an infection, resulting in impetigo.

Anyone can get impetigo — and more than once, Smith says. Although impetigo is a year-round disease, it occurs most often during the warm weather months. There are more than 3 million cases of impetigo in the United States every year.

“We typically see impetigo with kids 2 to 6 years old, probably because they get more cuts and scrapes and scratch more. And that spreads the bacteria,” Smith says.

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.

Look for these signs of impetigo:

• itchy red sores that fill with fluid and then burst open, forming a yellow crust
• itchy rash
• fluid-filled blisters

If you see those symptoms, visit your health care provider. Impetigo is usually treated with topical or oral antibiotics. If you have multiple lesions or if there is an outbreak, your doctor might prescribe an oral antibiotic. There is no over-the-counter (OTC) treatment for impetigo.

Untreated, impetigo often clears up on its own after a few days or weeks, Smith says. The key is to keep the infected area clean with soap and water and not to scratch it. The downside of not treating impetigo is that some people might develop more lesions that spread to other areas of their body.

And you can infect others. “To spread impetigo, you need fairly close contact — not casual contact — with the infected person or the objects they touched,” he says. Avoid spreading impetigo to other people or other parts of your body by:

• Cleaning the infected areas with soap and water.
• Loosely covering scabs and sores until they heal.
• Gently removing crusty scabs.
• Washing your hands with soap and water after touching infected areas or infected persons.

Because impetigo spreads by skin-to-skin contact, there often are small outbreaks within a family or a classroom, Smith says. Avoid touching objects that someone with impetigo has used, such as utensils, towels, sheets, clothing and toys. If you have impetigo, keep your fingernails short so the bacteria can’t live under your nails and spread. Also, don’t scratch the sores.

Call your health care provider if the symptoms don’t go away or if there are signs the infection has worsened, such as fever, pain, or increased swelling.

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.

Wound Care

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)

Hygiene

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.

Antibiotics

People diagnosed with impetigo can return to work, school, or daycare if they:

1. Have started antibiotic treatment
2. 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.