Impetigo: symptoms and causes

Impetigo is an infectious disease that mainly affects children. It is estimated that about 1% of European children have suffered from this disease. In Latin America the percentage rises to 15%. It is not a serious problem, but it can lead to important consequences.

Cases of impetigo in adults are rare. However, this disease can occur at any age. Typically, it takes place in childhood, in children between the ages of 2 and 6. At that stage there are no fully grounded hygiene habits and there is a lot of physical contact between the little ones.

In the case of impetigo, it is important that it be dealt with in the shortest possible time. Although in principle it is not serious, instead it is very contagious and expands rapidly. Likewise, in some children it can trigger postinfectious glomerulonephritis, which is a serious problem.

What is impetigo?

Children are the most affected by impetigo, a skin infection that is caused by bacteria and whose clinical manifestations include the appearance of sores on the face.

Impetigo is a skin infection caused by bacteria. It usually appears in the form of red sores on the face. These are preferentially located near the mouth or nose. It is also possible to find them on the hands and feet. These sores burst and give rise to honey-colored scabs.

The infection takes place in the epidermis, which is the most superficial area of ​​the skin. In this there is a layer called keratin, which acts as a protector of contact with the outside. If this layer is weakened or damaged, it allows the passage of the bacteria that cause impetigo.

There are basically three types of impetigo:

  • Bulky. It is caused by staphylococci and leads to the formation of blisters on the skin.
  • Not bullous. It is caused by the strep bacteria and instead of forming blisters, it erodes the skin. It is the most common modality.
  • Ectima type. It generates ulcers, instead of blisters or erosions.


The first symptom of this disease is a reddening of the skin, as if something had irritated it. A growing itching also appears. A little later sprout small blisters or vesicles. These have a very thin cover, which breaks easily.

When they burst, blisters or vesicles let pus out. This substance is highly contagious and any contact with it should be avoided. The skin is left alive and has blood. It is usual that there are some specially resistant blisters. These have a yellowish crust around them.

It is very common to swell the nodes near the affected area. These can be moved by moving them and it is not uncommon for them to generate pain. However, it is a symptom that often goes unnoticed. There is no fever or discomfort, since it is a localized and superfluous infection.

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Causes of impetigo

Impetigo is caused by bacteria such as Streptococcus pyogenes and the Staphylococcus aureus . It is a highly contagious infection.

Impetigo is usually caused by bacteria Staphylococcus aureus or by Streptococcus pyogenes. The latter is also known as "group A streptococcus" and is a cause of strep throat. The disease is acquired by direct contact with someone infected.

If the child scratches and then touches some other part of his body, You can move the infection to that new area. The disease is also spread by touching items that have been in direct contact with the skin, such as clothes, towels, etc.

The main risk factors of impetigo are the following:

  • Age. It mainly affects children between 2 and 6 years old.
  • Overcrowding. The spread expands in places with a lot of concentration of children.
  • Weather. Impetigo occurs most frequently in hot and humid climates, and in summer time in countries that have seasons.
  • Skin lesions. Typically, impetigo bacteria enter the skin through small wounds, such as insect bites or similar lesions.

Discover: Herpes zoster

Other data of interest

Although not common, the disease can also occur in adults. Those who are most exposed to it are those who have weakened immune systems, either by the use of any medication or by another disease. Diabetics are also a population at risk.

It is normal for sores to heal after a while and leave no scars. Only in rare cases do complications occur. The most common are marks or scars, kidney problems or deforming dermatopaniculosis.

Usually the disease is treated with antibiotics. It is recommended that the child does not attend school until at least 24 hours after starting treatment. In some cases it is recommended to cover the affected area with a dressing or gauze.