Impetigo

Impetigo is a skin infection that's very contagious but not usually serious. It often gets better in 7 to 10 days if you get treatment. Anyone can get it, but it's very common in young children.

Posted 15/4/2020 Dr James Britton - Consultant Dermatologist

Impetigo is the name for a skin infection caused by a bacteria called staphylococcus aureus. This infection is more common in children, though can also affect adults.

Impetigo commonly affects the area around the mouth and nose. The reason for this is that 40% of people can carry the bacteria harmlessly in their nose. The bacteria can fall out of the nose to infect the skin nearby, so the areas around the mouth and nose are the most common areas to be affected.

Treating impetigo involves the following:

topical treatments (antibiotics, steroids if needed and moisturisers)
physical treatments (removing crusts etc)
systemic treatment if necessary - treatment taken by mouth in tablet or syrup form.

Causes of impetigo

This is an infection with staphylococcus aureus the bacteria that causes impetigo and can make eczema flare up. Occasionally the bacteria makes a toxin that causes skin to split and blister. The blister is very shallow and does not scar.

Skin barrier and impetigo

If the skin is dry in any way the bacteria (staphylococcus aureus) that causes impetigo can stick to the skin and then can cause the condition...this is why if you have dry stkin and eczema it is crucial to use moisturisers carefully.

Making the diagnosis and tests for impetigo
Remember that impetigo is common in children. A dermatologist will be able to assess pictures or see someone face to face to give a diagnosis as well as your family doctor who has experience in diagnosis and treatment of skin problems.

You can take a swab (specimen of the skin) and send this to the laboratory to grow the bacteria to confirm the diagnosis.

Remove any crust
Remove the crust by washing carefully with warm water. Using a moisturising cream as a soap, gently rubbing the area to remove the crust is simple and effective. The reason for this is that treatments that are then put directly onto the skin will be more effective rather than being applied on top of the crust.

Antibiotic treatments to the skin
Topical antibiotic creams can be applied to the area as a simple treatment alone in mild to moderate cases. Washing in an antiseptic is commonly advised.

Topical fusidic acid has been shown to be more effective than placebo in treating impetigo in a Dutch study:

Fusidic acid cream in the treatment of impetigo in general practice: double blind randomised placebo controlled trial BMJ 2002; 324: 203 BMJ 2002; 324: 203

Antibiotic treatments taken by mouth
More severe cases may require antibiotics taken by mouth in tablet form or syrup for children. The usual antibiotic treatment is flucloxacillin. This may be used for 5 to 7 days though the exact length of time for optimum treatment is not known. It may be that only three days is needed of a higher dose. A long course is not needed as staphylococcus aureus does not recur like a streptococcal infection.

Moisturisers on the skin
Moisturisers may be needed to treat any dry skin and also can relieve the tenderness and pain that can be caused by the impetigo. To be the most soothing: apply a large amount and smear on and do not rub in.

Topical steroids

Topical steroids may be used to reduce the inflammation. A mild steroid or moderate steroid may be used.

Topical steroids and antibiotic treatment
Plain topical steroids can be used alone with antibiotics that are taken by mouth. If an antibiotic is taken by mouth then an antibiotic on the skin is probably not needed.

A topical antibiotic in combination with a topical steroid can be used for milder to moderate cases of impetigo.

It would not be good practice to combine one type of topical antibiotic with another antibiotic taken by mouth.

Difficult cases that come back

If this occurs then it is possible that a close contact such as a brother or sister or a parent may be carrying the bacteria staphylococcus aureus and passing it around family members.

To find this out, swabs can be taken from the nostrils of each family member and sent for culture.

The alternative is to treat the close contacts such as the whole family by giving a topical antibiotic to put up the nose three times daily for a week and for each family member to wash in an antiseptic.

For an individual that has recurent cases of impetigo the treatment of the nose as a possible site of Staphylococcus aureus carriage may be needed.

This would involve putting the antibiotic cream up the nostrils three times per day for 7- 10 days.

The other consideration may be overwashing of the area of skin, so damaging it and making it more susceptible to infection. In this case avoiding washing with soap and using moisturiser may be needed.

Washing the skin
It is important to recognise that the skin is designed to cope with bacteria growing on it. This is by losing old dead skin cells constantly so bacteria are also are rubbed off the skin naturally.

This process is damaged by the misguided overwashing that often happens, based on the wrong assumption that washing can "clean" the skin.

Impetigo is caused by the bacteria staphylococcus aureus, which can be passed from individual to indiviual by close contact. Impetigo is NOT as easily caught as influenza which is highly contageous (very catching!).

Precautions for family members
Careful handwashing washes the bacteria off the skin. Separate towels and washing flannels should be used for each family member to use. This is because the bacteria can be rubbed off onto the flannels which can then be rubbed on the face of another person who uses the same one.

Other family members who have eczema should have their moisturising treatment improved to help keep their skin supple, protecting them against the bacteria getting a hold on dry cracked skin.

Precautions for schools
The individual who has impetigo may go back to school one or two days after treatment has started. Similar steps should be taken as for family members, with separate towels for drying used, particularly after sport and handwashing.

Outbreaks

Outbreaks can occur in schools or anywhere that a lot of people come together in close contact. In this situation the numbers of the bacteria increases dramatically when it is found on surfaces, towels, curtains and basically everywhere that is touched.This can be easily sorted by careful handwashing as this washes the bacteria off the skin.In an outbreak it may be considered necessary to test individuals to see if they are carrying the bacteria up the nose, by taking swabs. However, this would be a big task if a lot of people are involved.Treating the close contacts may be required. This would be with an antibiotic cream up the nostrils three times daily for a week and washing in antiseptic is a simple and effective measure to reduce the amount of the bacteria being carried in a group.

History example of impetigo

"It started by our child - a 6 year old boy - accidently scratching his arm. "
Within two days it rapidly became about two inches in diameter, from something that was no bigger than a pin prick in size.Two days later it had become about three inches diameter.

Both the parents and the local chemist believed it to be an allergic reaction to plasters.

The parents then sprayed his arm with Savlon dry antiseptic (as advised by chemist) and covering with Melolin patches, but more skin appeared to be sticking to the patch.
"So we sought the advice of the hospital and a diagnosis of bullous or blistering impetigo was made."

We hope this information is useful to you.

If you need an opinion and treatment plan for any skin condition that you think may be impetigo then you can register at www.MyHealthFile.me and upload your pictures and history. A specialist dermatologist will give you a reply within 24 hours.