At a glance

  • Impetigo is a contagious rash.

  • It causes itchy blisters to form, particularly on the face, and then develop into yellowish crusts.

  • It is most common in children.

  • They shouldn't return to daycare or school while they're still contagious.

  • Antibiotic creams are an effective treatment.

Introduction

Photo of a mother and her children at the doctor's (PantherMedia / CandyBox Images)

Impetigo is an itchy and sometimes painful infection of the outer layers of skin. It is especially common in young children. The infection is caused by bacteria and is highly contagious. For that reason, children who have impetigo aren't allowed to return to school or daycare until they're no longer contagious – about 24 hours after the start of treatment with antibiotics. Without treatment, impetigo can remain contagious for several weeks.

Symptoms

The first signs of impetigo can usually be seen around the mouth and nose in the form of an itchy reddish rash with small blisters. The blisters are filled with water or pus and burst easily. Once they have burst, yellowish crusts form. These fall off after some time without scarring. As well as on the face, impetigo can occur on the arms and legs.

 Illustration: Yellowish crusted-over impetigo blisters – as described in the articleYellowish crusted-over impetigo blisters

 

In rare cases, larger blisters develop and don't break open as quickly. This type of impetigo (bullous impetigo) affects the neck and torso, and may be found in the armpits or in the groin area, for example.

It sometimes also causes fever and swollen lymph nodes.

Causes and risk factors

Impetigo is a bacterial infection, usually caused by Streptococcus or Staphylococcus bacteria. These germs can enter your skin in different ways, including through minor cuts or scrapes, a rash or an insect bite.

They spread to other people through skin contact, or through contact with objects that an infected person has touched.

Prevalence and outlook

Impetigo is the most common skin infection in children. It is less common in adults. In Europe, about 2 out of 100 children are treated for impetigo every year.

The typical rash appears about 2 to 10 days after infection.

It usually goes away within three weeks, even without treatment. But it can also take a few more weeks, and you remain contagious the entire time.

Complications (such as the rash spreading to deeper layers of skin) are rare, even without treatment. Unfortunately, having impetigo doesn't make you immune to the bacteria, so you don't have any protection from new infections.

Diagnosis

Doctors can often tell whether it's impetigo just by looking at it. Further testing – like a swab test to determine what kind of germs there are – usually isn't needed. But it can help if doctors can't rule out other possible skin diseases, like a fungal infection.

Prevention

General hygiene rules can prevent many types of infections, including impetigo. They mainly include washing your hands with soap and water before you eat, after you go to the toilet and after you've spent time outdoors. Other than that, there's not much in particular that you need to do to prevent you or your children from getting impetigo.

But you do need to take special precautions if a child has impetigo or has a rash that could be impetigo: Then it's important to prevent others from becoming infected. For example, the child shouldn't go to daycare centers, schools or any other places where they are in groups with other children. Their parents or legal guardians are required by law to report to the school or daycare center that their child has impetigo or is thought to have it.

The child can only return once a doctor has decided that he or she is no longer contagious. This is typically 24 hours after the start of treatment with antibiotics, or after the impetigo has cleared up on its own (without treatment).

To prevent the infection from spreading within the family, it's important to

  • frequently wash your hands with soap and water (even when at home),
  • avoid touching the rash,
  • use separate towels, and
  • wash underwear (and if possible all other clothing), used towels and bedsheets at a temperature of at least 60 °C (140 °F).

Treatment

As long as impetigo doesn't spread beyond a small patch of skin, disinfectant solutions or creams are often recommended. But it isn't clear whether they work.

Antibiotic creams have proven effective. You can use a wooden spatula or disposable gloves to avoid touching the rash with your bare hands.

Antibiotics that are swallowed (oral antibiotics) are usually only prescribed if a child has impetigo on a large area of skin or if several parts of their body are affected. Antibiotic tablets are more likely to have side effects than antibiotic creams are. For instance, they may cause gastrointestinal (stomach and bowel) problems.

It's a good idea to keep the child’s fingernails trimmed very short so they can't scratch themselves as much.

Research summaries

Further information

When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.