Impetigo
Key facts
- Impetigo is a very common skin infection that causes skin sores and blisters.
- Impetigo is caused by staphylococcus or streptococcus bacteria.
- Impetigo usually affects young children, as the infection can easily spread in places such as schools and childcare centres — this is why it is sometimes called ‘school sores’.
- Your doctor can diagnose impetigo by looking at your sores and may also take a swab to test for bacteria.
- Impetigo is usually treated with antibiotics in the form of a cream, ointment, tablets or syrup, depending on the severity of the condition .
What is impetigo?
Impetigo is a very common skin infection that causes sores and blisters. It affects mainly children. It’s sometimes called ‘school sores’.
Impetigo is contagious and can be very dangerous for newborn babies. It’s important to keep children who have impetigo away from babies and they should not go to school or childcare until 24 hours after antibiotic treatment has been started, or until the blisters have dried out.
What are the symptoms of impetigo?
Impetigo causes sores on the skin. These blisters can grow quickly and then burst, leaving a moist area with a brown crust at the edge. The blisters can be large (several centimetres across) and itchy. Sometimes, the sores have a thick, soft, yellow crust with a moist red area underneath.
Small blisters can join to form large, loose, floppy blisters. This is called bullous impetigo.
The sores appear 1 to 3 days after exposure to the infection. They are contagious as long as there is fluid weeping from them. They are no longer contagious when they have scabbed over or 24 hours after starting antibiotic treatment.
Other symptoms may include a fever, swollen lymph nodes (glands) or feeling generally unwell.
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What causes impetigo?
Impetigo is caused by staphylococcus or streptococcus bacteria. The bacteria may penetrate the skin if it is scratched or broken due to conditions such as:
Impetigo usually affects young children, because the infection spreads easily in places such as schools and childcare centres.
Impetigo in adults is more common when people are living in a confined area, such as army barracks, or if someone has a lowered immune system.
When should I see my doctor?
Speak to your doctor if you or your child has symptoms of impetigo. Impetigo is not usually serious, but it may be confused with other skin conditions such as cellulitis, contact dermatitis and insect bites. Your doctor will be able to rule these out.
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How is impetigo diagnosed?
If you think you or your child may have impetigo, see your doctor. They can diagnose it by examining your skin and looking at the sores. They may also take a swab to test for bacteria and identify the most effective treatment.
How is impetigo treated?
Antibiotics are usually prescribed in the form of a cream, ointment, tablets or syrup depending on the severity of the condition. Always complete the full course of treatment that your doctor prescribes. This will help prevent the infection from coming back and reduce the chance of antibiotic resistance.
Here are some other things you can do to help manage impetigo and stop it spreading:
- Wash sores with salty water (1 teaspoon of table salt dissolved in a cup of hot water and left to cool) 2 to 3 times a day. Pat dry, using a new or single-use towel each time, then apply the antibiotic cream as prescribed.
- Cover sores with waterproof dressings to prevent the spread of infection. Throw all dressings in the bin straight after you take them off and wash your hands.
- The affected area can become irritable and itchy. It is important to not scratch it because it can make the impetigo spread and get worse.
- Practice good hand hygiene and keep your fingernails cut short.
Can impetigo be prevented?
Most people are no longer contagious after 48 hours of treatment, or once their sores have dried and healed. Avoid childcare, school or work until you are no longer contagious.
To minimise the risk of impetigo spreading, it's also best to:
- avoid touching the sores
- wash your hands regularly, especially after applying cream to the sores
- keep children out of childcare, playgroup or school until their sores have dried up
- avoid sharing anything that comes into contact with your skin, such as face cloths, towels, clothes and bath water
Complications of impetigo
Complications of impetigo are rare. However, sometimes the infection can spread to the lymph nodes (lymphadenitis), or to a deeper layer of skin (cellulitis).
Resources and support
For more information about the symptoms, diagnosis, management and prevention of impetigo see the NSW Health and WA Department of Health fact sheets.
Call Pregnancy, Birth and Baby on 1800 882 436 or via video call to speak to a maternal child health nurse. Hours are from 7 am to midnight (AEST/EADT), 7 days a week (including public holidays).
Call healthdirect on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.
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Last reviewed: November 2023
