Key points
- Impetigo is a skin infection that starts as a red, itchy sore.
- In general, impetigo is a mild infection that can occur anywhere on the body.
- Healthcare providers treat impetigo with antibiotics.
What it is
Impetigo is a skin infection caused by bacteria: either group A Streptococcus, Staphylococcus aureus, or both. This page focuses on impetigo caused by group A Streptococcus (group A strep bacteria).
Did you know?
Symptoms
It usually takes 10 days for sores to appear after someone is exposed to group A strep bacteria.
Symptoms include red, itchy sores that break open and leak a clear fluid or pus for a few days.
The sores can occur anywhere on the body but most often affect exposed skin.
Sores are commonly found on the following areas:
- Arms
- Legs
- Mouth
- Nose
Next, a crusty yellow or "honey-colored" scab forms over the sore, which then heals without leaving a scar.
Complications
Very rarely, complications can include post-streptococcal glomerulonephritis and rheumatic fever.
Post-streptococcal glomerulonephritis is a kidney problem.
Rheumatic fever is a disease affecting the heart, joint, brain, and skin.
Risk factors
Anyone can get impetigo, but some factors increase the 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.
Group settings
Close contact with another person with impetigo is the most common risk factor for illness. For example, if someone has impetigo, the bacteria often spread to other people in their household.
Crowded conditions can increase the risk of spreading impetigo. These settings include:
- Daycare centers and schools
- Detention or correctional facilities
- Homeless shelters
- Military training facilities
Climate
Impetigo can occur anywhere. It is more common in areas with hot, humid summers and mild winters (subtropics), or wet and dry seasons (tropics).
Poor personal hygiene
Lack of proper handwashing, body washing, and facial cleanliness can increase someone's risk of getting impetigo.
Causes
Group A Streptococcus (group A strep bacteria) cause impetigo and are contagious.
Prevention
There are things people can do to protect themselves and others from group A strep infections, including impetigo.
Testing and diagnosis
Healthcare providers typically diagnose impetigo by looking at the sores during a physical examination. Lab tests are not needed.
Treatment and recovery
When to return to work or school
Healthcare providers treat impetigo with antibiotics. They can be topical antibiotics (medicine rubbed onto the sores) and oral antibiotics (medicine taken by mouth).
A healthcare provider might recommend a topical ointment for only a few sores. Oral antibiotics can be used when there are more sores.
Use the prescription exactly as the healthcare provider says to.