Contagious Impetigo Explanation

Contagious Impetigo

Impetigo contagiosa is a highly contagious bacterial infection that occurs primarily in newborns and children. In principle, however, the infection can occur at any age. Synonyms are pus lichen, scab lichen, bark lichen or train. The face and extremities are mostly affected.

What is contagious impetigo?

If the child shows symptoms of a skin disease, they should be taken to the pediatrician on the same day. External signs such as pus blisters, yellowish crusts or redness indicate that it is impetigo contagiosa – a disease that must be treated by a doctor in any case.

According to abbreviationfinder, impetigo contagiosa is one of the bacterial infections of the skin. It is common and highly contagious. Although the infection can affect any age, children and newborns are most commonly affected.

There are two forms of impetigo contagiosa that are caused by different bacteria. The small blister form is caused by group A beta-hemolytic streptococci. The causative agent of the large blistered form is Staphylococcus aureus.

The incubation period is two to ten days. There is a risk of infection as long as open, purulent areas of skin have not yet healed. During this time, the blisters and their contents are highly contagious.


Impetigo contagiosa is transmitted by a smear infection with the bacteria mentioned. The bacteria are also found in the nose and throat of many healthy people.

The disease occurs when the pathogen penetrates the bloodstream through scratched or injured skin and can destroy tissue there. Therefore, for example, children with neurodermatitis, chickenpox or scabies are particularly susceptible to impetigo contagiosa.

The bacteria are transmitted through direct contact or dirty hands (smear infection). They also survive on glasses or other objects for long periods of time. Indirect transmission is also possible if a contaminated object is used by several people. Of course, the infection spreads particularly easily in community facilities such as schools or kindergartens.

Symptoms, Ailments & Signs

The three forms of impetigo contagiose are expressed by predominantly uniform symptoms. The small, white to reddish blisters on the skin are typical. These skin lesions, which are very small and therefore hardly visible in the non-bullous form, burst open after a while and yellowish crusts form.

Then there is often itching. The blisters can appear in one spot or over a large area. In a severe infestation, a large part of the skin is affected. In the case of small blistered impetigo contagiosa, the blisters are small and filled with pus, and burst open after a few days due to their thin skin. Large blistered impetigo contagiosa is manifested by larger skin changes with thicker skin.

They are clear at the beginning and slowly become cloudy. The blisters burst after one to two weeks, leaving behind the characteristic crusting. Non-bullous impetigo contagiosa produces few or no blisters, although yellowish crusts still appear. In rare cases, the changes in the skin are accompanied by a fever. The increased body temperature is accompanied by typical symptoms such as chills and malaise and subsides after a few days.

Diagnosis & History

The doctor can make a diagnosis of impetigo contagiosa based on a visual diagnosis, since the rash is typical of the disease. A skin swab (including swabs from the nose and throat) is also possible in order to be able to prove the pathogen in case of doubt. In the differential diagnosis, the doctor excludes a herpes simplex infection.

The rash in impetigo contagiosa is typical. The patient shows golden-yellow crusts with a red border, which mainly appear in the area of ​​the mouth and nose and on the hands.

First, the skin is slightly red and blisters filled with fluid or pus form. In the small-vesicle form, the wall of the vesicle is very thin and bursts easily. This causes the disease-typical honey-yellow scab to form .

In the case of large-blistered impetigo contagiosa, the patient can also develop fever and show swelling of the lymph nodes. The fluid in the blisters is highly contagious. The crust formation is stronger in the small blistered form than in the large blistered impetigo contagiosa.

Eventually, the skin flakes fall off on their own or can be removed by hand. With consistent therapy and compliance with hygienic regulations, the infection usually heals without consequences.

However, complications can also occur during the disease. The patient can develop postinfectious glumeronephritis, lymphadenitis, or regional lymphangitis.


The impetigo contagiosa mainly causes complaints on the extremities and on the face of the patient. In most cases, blisters form on the skin and the affected person suffers from a severe rash. This rash can be itchy, and blisters filled with pus can also form.

The patient’s quality of life is significantly reduced by impetigo contagiosa and there is often a reduced sense of self-esteem due to the aesthetic limitations. It is not uncommon for those affected to suffer from inferiority complexes and depression. They withdraw from social life and also suffer from severe exhaustion.

Swelling of the lymph nodes and the development of fever can also occur. The affected person also suffers from reduced resilience. There are no further restrictions or complications in the treatment of impetigo contagiosa.

This usually takes place with the help of antibiotics and also leads relatively quickly to a positive course of the disease. The patient’s life expectancy is not reduced by the disease. However, in severe cases, scars can form.

When should you go to the doctor?

If the child shows symptoms of a skin disease, they should be taken to the pediatrician on the same day. External signs such as pus blisters, yellowish crusts or redness indicate that it is impetigo contagiosa – a disease that must be treated by a doctor in any case. Parents who notice such symptoms in their child should consult a dermatologist immediately . This is especially true if the child complains of increasing pain and itching.

At the latest when the blisters open or even become inflamed, the child needs medical attention. Children who have recently had chickenpox or scabies or suffer from neurodermatitis are particularly susceptible to impetigo contagiosa. Parents should consult a doctor if they notice the above symptoms associated with any of these conditions. If the symptoms are severe, the child should be taken to a hospital. Further treatment is carried out by a dermatologist or an internist.

Treatment & Therapy

Because of possible sequelae, the doctor treats impetigo contagiosa in severe cases systemically with antibiotics (amoxicillin or flucoxacillin).

For the affected areas of skin, the doctor will also prescribe ointments containing antibiotics, such as fusidic acid, mupirocin or retapamulin. Baths and poultices with disinfectant solutions are also helpful.

Outlook & Forecast

With expert treatment, the prospects for curing impetigo contagiosa are very good. The bark lichen often heals spontaneously. Nevertheless, those affected with impetigo contagiosa should not wait and see if this happens. It’s safer to start treating the infection and avoid spreading the ringworm to other areas of the skin. Even with medical treatment, it can take weeks for all signs of ringworm to go away.

The affected skin areas later show purulent pustules, which open quickly and leave yellow crusts. This is not only unsightly, but also contagious. The infection will therefore spread if the person concerned does not take it seriously enough and spreads germs through misconduct.

The spread of impetigo contagiosa to other skin areas can certainly lead to secondary diseases. In the case of purulent inflammation of the conjunctiva (conjunctivitis), the eyes are affected, and in the case of inflammation of the middle ear (otitis media), the ears are affected. In addition, glomerulonephritis can occur in longer courses. That worsens the prognosis.

Depending on whether staphylococci or streptococci have triggered the impetigo contagiosa, further consequences can occur if the infection is left untreated. Staphylococci, for example, can cause sepsis or inflammation of the lymphatic system. Untreated streptococcal infections can cause kidney damage such as post-infectious glomerulonephritis.


A spread can only be prevented by consistently complying with all hygienic measures. The patient himself should under no circumstances scratch the highly infectious blisters. In the case of children, parents can therefore also cut their fingernails as short as possible.

Regular hand washing of the patient and of course all contact persons is essential. All clothes worn by the patient and all towels used as well as bed linen must be boiled at 60°C.

This can contain the infection and prevent it from spreading. In order to avoid infecting other people, the patient may only visit community facilities such as schools or kindergartens again when the infected skin areas have healed completely. This is the case when the crusts have completely fallen off.


In the case of impetigo contagiosa, in most cases the affected person has no special options for aftercare. The earlier the disease is detected, the better the further course is, so that the person affected should ideally see a doctor as soon as the first signs and symptoms appear. Self-healing cannot occur with impetigo contagiosa.

In most cases, the disease is treated by taking various medications. If antibiotics are administered, the person concerned should not take them together with alcohol, as this will significantly reduce their effect. It is also important to ensure that it is taken regularly and that the dosage is correct.

If anything is unclear or if you have any questions, you should always consult a doctor first. Furthermore, no special measures are usually necessary. Impetigo contagiosa does not reduce the life expectancy of those affected. However, the patient should take it easy and rest. In any case, exertion or stressful activities should be avoided in order not to unnecessarily burden the body.

You can do that yourself

In the case of impegno contagiose, medical treatment is required in any case. Medical therapy can be supported by some self-help measures and various household and natural resources.

The most important measure is to peel off the crusts twice a day. An antiseptic solution is required for this, which softens the incrustations and thus prevents injuries to the skin. The wound can then be treated with an antiseptic ointment or a local antibiotic and closed with a fresh bandage. When removing the crusts, thorough hygiene must be observed, otherwise inflammation can occur. If larger areas of skin are affected, disinfecting baths with quinolinol or potassium permanganate are recommended. If it is chronic, treatment with antibiotics is required.

Both medical preparations and strict hygiene measures help against the itching. Those affected should wash their hands frequently and thoroughly and not bathe with other family members or their partner. In addition, the fingernails should be trimmed regularly and the towels should be washed hot after use. Those affected should take sick leave for at least one to two weeks. Only when the doctor gives the all-clear can direct physical contact with other people be resumed.

Contagious Impetigo