Impetigo: causes, symptoms, and treatment

Impetigo is also known as school sores or impetigo contagiosa. Impetigo is an itchy and sometimes painful infection of the outer layers of skin. It is especially common in young children. This 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.

The first signs of impetigo can usually be seen around the mouth and nose in the form of an itchy red rash with fluid-filled blisters which burst easily and form yellowish crusts. These fall off after some time without scarring. The arms and legs may be affected in addition to the face.

In rare cases, large blisters form on the skin and do not immediately burst. Impetigo with blisters (known as bullous impetigo) can occur on the neck and on the trunk of the body, for example, in the armpits or in the diaper area.

They are sometimes accompanied by fever or swollen lymph nodes.

Impetigo is an infection caused by certain bacteria, usually Streptococcus or Staphylococcus bacteria. These germs can enter the 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.

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

The rash that typically occurs with impetigo appears around two to ten days following infection. Impetigo often clears up on its own within three weeks. However, it may persist for several more weeks and people remain contagious for the duration.

In rare cases, complications may occur without treatment – for example, the infection can spread into deeper layers of the skin. Having had impetigo doesn’t make you immune to the bacteria, so you don’t have any protection from new infections.

Impetigo can be avoided through general hygiene measures. These include, in particular, regular handwashing with soap before eating and after using the toilet or outdoor activities. Otherwise, there is no specific advice for avoiding impetigo in adults and children in everyday life.

Further measures are only necessary if a family member has already become ill. To avoid infecting the other members of the family, it is important to:

• wash hands frequently with soap, including when at home
• avoid touching the rash
• use personal towels
• wash underwear (and, if possible, all clothing), used towels and bedding at a temperature of 60°C or higher

Doctors can often tell whether it’s impetigo just by looking at it. Further testing on the skin – 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. 

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, however, proven effective. To avoid touching the rash, ointments can be applied with a wooden spatula or while wearing disposable gloves. 
Antibiotics tablets are usually only prescribed if a child has impetigo on a large area of skin or if several parts of their body are affected. Antibiotics that are swallowed are more likely to have side effects than antibiotic creams are. For instance, they may cause gastrointestinal (stomach and bowel) problems, such as nausea and diarrhea.

If blisters burst, they are more likely to become inflamed. To prevent intense scratching in an infected child, it is helpful to keep the fingernails as short as possible.

You can find more detailed information, for example, how to help impetigo to heal more quickly, at gesundheitsinformation.de.

Impetigo is among the infections recorded in the Infectious Diseases Protection Act. This means that everyone who suspects they could have impetigo should stay away from places where people are gathering to avoid contact with others. Children are not permitted to attend kindergarten or school and should not play with other children. In addition, parents and guardians have a legal obligation to notify the relevant authority if a child has or is suspected of having an infection.

Activities with other people are only allowed again once a doctor determines that there is no longer any risk of infecting others. If antibiotics are prescribed, they are usually taken about 24 hours after the start of treatment. Without treatment, impetigo only stops being contagious when it heals by itself.