Child with impetigo on his lower lip.
Impetigo on the lower lip.

What is impetigo?

Impetigo is a common skin infection, usually caused by the Staphylococcus aureus, or “staph” bacteria. Some cases are caused by Group A streptococcus bacteria, a type of bacteria that can also lead to strep throat and scarlet fever.

Certain strains of strep bacteria that cause impetigo can lead to the development of the inflammatory kidney disease glomerulonephritis. This disease can cause high blood pressure and blood in the urine.

Who can get impetigo?

Impetigo usually affects children between the ages of two and six, although older children and adults can also get it.

What are the symptoms of impetigo?

Impetigo is a fairly mild but highly contagious disease. Symptoms include:

  • One or more pus-filled blisters that can burst easily and leave behind red, raw skin
  • Itchy blisters that contain yellow or tan fluid that seeps and forms a crust
  • A rash that often spreads
  • Skin lesions, usually on lips, nose, ears, arms, and legs. These can spread to other areas of the body.
  • Swollen lymph nodes close to the area of the infection

In cases of impetigo caused by staph bacteria, symptoms include reddish skin surrounding red blisters that are full of clear liquid or pus that eventually will look cloudy. These blisters can easily burst and leak. Once broken, there is a raw, shiny area that will scab over with a light yellow/brown crust.

Once an infection occurs, it can take up to three days before symptoms occur. The sores can itch; scratching them usually spreads the infection.

How does someone get impetigo?

When the skin is opened or punctured from a cut, bite, or scratch, the bacteria can get under the skin, which can lead to infection. Impetigo can also infect the skin even when it is not broken open. The infection occurs more often in warmer months, when children are typically outside more.

How does impetigo spread to others?

Impetigo can be spread by coming into contact with the sores or any mucus/nasal discharge from someone who is infected. It can also spread by sharing household items, such as towels, clothing, or other personal care products, with someone who has the disease.

Impetigo is contagious until the rash disappears, the scabs fall off, or the patient has completed at least two full days of antibiotics. Children are prone to scratching open their scabs, and are at risk of re-infection.

Last reviewed by a Cleveland Clinic medical professional on 02/20/2017.


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