Health Guide: 

Impetigo Update:

School sores (pokenga kiri whēwhē) is the common name for impetigo, a highly contagious skin infection most often seen in children.

Key points

1. Impetigo is caused by two types of bacteria: Streptococcus pyogenes (strep) or Staphylococcus aureus (staph).
2. It causes sores on your skin, generally on your hands and face, especially around your nose and mouth. It can also affect other areas of your body.
3. It easily spreads from one person to another and is most common in children. 
4. Children should see a doctor for assessment and treatment. Your doctor may advise careful cleaning of the sores and using antiseptic or antibiotic cream. Sometimes oral antibiotics are prescribed.
5. Children should be kept away from school or daycare to avoid spreading to other children. They can go back one day after the start of treatment and when the sores are completely covered with dressings. 

What are the causes of impetigo?

Impetigo is a common skin infection caused by two types of bacteria: Streptococcus pyogenes (strep) or Staphylococcus aureus (staph). Some people carry these bacteria in their nostrils, on the skin or in the throat. It can be transferred to the hands and then onto other parts of the skin. 

Most of the time, your skin is an effective barrier that keeps bacteria out, and these bacteria can live on your body without causing problems. When there is a break in your skin, such as a cut or graze, bacteria can enter your body. It can then grow, causing inflammation and infection. Breaks in your skin may happen with bites (insect, animal or human) or injury. Impetigo may also occur on healthy skin where there is no visible break.

Who is at risk of impetigo?

Impetigo is most common in children. In adults, it may follow other skin disorders. It is also more common in people with a weakened immune system. Impetigo can be spread to other people by contact with the sores. The sores are most infectious when there is weeping or crusting on them and should be kept clean and covered. It can also spread by contact with infected clothing, towels or playthings. 

What are the symptoms of impetigo?

Impetigo usually starts as little blisters. These then break and start to weep, usually pus or sometimes a clearer liquid. The weeping patches tend to grow larger. Yellow or brownish scabs then form. These can burn or itch.

Impetigo can also start as any lesion (bite, damaged skin) that doesn't heal and develops a crusty scab. Sometimes it looks like a rash – which may begin as a single spot, but if you scratch, it may spread to other areas. You may develop swollen lymph nodes.

How is impetigo diagnosed?

• Impetigo can usually be diagnosed based on how it looks and a description of how it came about. See images of impetigo from DermNet
• Sometimes a skin swab is needed if it keeps coming back or doesn't get better with treatment.
• A swab is also taken if there is concern that an antibiotic-resistant strain of bacteria such as MRSA is the cause.

What is the treatment for impetigo?

If you think your child might have impetigo, take them to the doctor. Treatment will depend on how severe the infection is.

For a mild infection, your doctor may prescribe an antiseptic or antibiotic cream to be applied every day. For more severe infection that is more widespread, your doctor may prescribe a course of antibiotics to be taken by mouth.

Clean off scabs and crusts

Remove the scab or crusted area by washing with an antiseptic solution such as Dettol or Savlon. Follow the instructions on the packaging or ask your pharmacist for advice on how to use them. You can also remove crusts by:

• giving your child a warm bath for 20 minutes and gently wiping crusts away with a wet towel. Wash towel after use.
• making up a mixture of half a cup of white vinegar in a litre of warm water and applying a cloth soaked in this mix to the sores for about 10 minutes 3 times a day. Gently wipe off the crusts.
• for more severe cases, your doctor may suggest you do bleach baths.  

Keep the sores covered. 

Keep the sores clean and cover with a watertight dressing or bandage to prevent them from spreading. Dressings and the correct tapes to hold the dressing in place can be purchased from pharmacies. Throw used dressings into a plastic bag and seal it before discarding.

Try to prevent your child from scratching the sores as much as possible. Keep your child's fingernails short to prevent damage and infection from scratching. Ensure your child washes their hands with soap often, especially if they touch the sores. 

Antiseptic or antibiotic cream

If your child is prescribed an antiseptic or antibiotic cream, apply it to the affected areas as prescribed by your doctor – usually 2 or 3 times a day. Examples of antiseptics are povidone-iodine, hydrogen peroxide cream or chlorhexidine and antibiotic ointments are fusidic acid or mupirocin.

• Before applying the cream or ointment, remove the crusted area as described above – see clean off scabs and crusts. 
• After applying the antiseptic or antibiotic, cover the sores with a dressing, as described above – see keep the sores covered.   
• Look carefully for new lesions to treat.
• Remember to wash your hands with soap and water before and after applying the cream or ointment to your child's skin.  

Antibiotic liquid or capsules

If prescribed antibiotic liquid or capsules (also called oral antibiotics), continue taking the medicine for the full course, even if the sores look to have healed. Oral antibiotics can sometimes have side effects. Report any diarrhoea, stomach upsets or skin rashes to your doctor or practice nurse.

In some cases, your doctor may also prescribe an ointment to rub on the inside of the nostrils for the child and other family members – the bacteria can hide out there and reinfect others.

How to avoid passing school sores on to others

School sores are highly contagious and are easily spread by touching. To avoid the spread, keep your child away from school or daycare until one day after the start of treatment and when the sores are completely covered with dressings. Other ways to prevent spreading school sores to others include:

• Wash your hands with soap and dry thoroughly before and after touching the skin or sores or applying the antiseptic.  
• Do not share towels, soap and face towels. Make sure each family member has their own.  
• Wash your child's clothes, towels and bed linen separately from the rest of the family. Wash them in hot water and dry them in the sunshine or with a hot tumble dryer. You can wash toys with a mild disinfectant.
• Put all used tissues and dressings in a rubbish bin with a lid. 
• Your child should avoid swimming until all the sores have healed.

For more information and support, talk to your doctor, practice nurse or your local pharmacist, or ask to speak to the public health nurse attached to the school. You can also phone Healthline free (within New Zealand) on 0800 611 116 for health advice.

Learn more

Images of impetigo DermNet NZImpetigo – school sores Kidshealth NZBleach baths for skin infections DermNet NZ

Phone Healthline for free on 0800 611 116 any time of the day or night for advice on any health issue, no matter how small. In an emergency, phone 111 for an ambulance.