- Impetigo is a skin condition caused by bacteria.
- Impetigo needs prompt attention because it is highly contagious.
- It mainly affects children.
- When correctly treated, impetigo leaves no ill effects.
Impetigo is a common and highly contagious superficial bacterial skin infection that affects children, especially pre-school and young children.
It usually affects exposed areas of the arms and legs and the face, especially around the nose and mouth. Infected areas may range from the size of a 20c to a R5 coin.
Impetigo is caused by bacterial infection of the skin. These bacteria are of two kinds, either staphylococci (Staph) or streptococci (Strep).
These kinds of bacteria are everywhere; in grimy bathrooms, in spoiled food and as part of the normal bacterial flora on or in our own bodies especially on our skin or in the nostrils.
They gain entry into the skin when a cut, crack, scratch, abrasion, insect bite or an area of eczema comes into contact with these bacteria.
Examples are bathing in a dirty bathtub or by using a towel or soap previously used by an infected person. People who also have other skin problems are more susceptible to impetigo.
Physical contact such as scratching an infected area can spread the bacteria to other parts of the body and even to other people.
Sharing clothing, bedding and other objects also spread the infection. Excessive sweating, malnutrition and poor hygiene can exacerbate the condition.
Who gets it and who is at risk?
Children– especially those at pre-school –are mainly affected by impetigo. They are also carriers of the infection because their activities involve large groups and close contact with each other.
Although impetigo is most common in children, almost anyone can get it. Those who live in poor hygienic conditions are more susceptible to impetigo, especially if they also have other skin problems.
Symptoms and signs
- The infection starts with a patch of swollen red skin that may develop into blisters.
- After a few hours the blisters break open into a red, moist area that oozes or weeps yellowish fluid.
- In a few days, a golden or honey-coloured crust is formed, resembling grains of brown sugar. The crust may continue to spread at the edges of the affected area.
- In severe cases, the infection invades deeper skin layers and develops into small ulcers in the skin called ecthyma. The ulcers of ecthyma are filled with pus and may be itchy. The crusts are darker and thicker than those of impetigo.
- If left untreated, permanent scars and changes of the colour of the skin may result.
A potentially serious complication of impetigo is nephritis, a kidney infection which is caused by some strains of streptococci. This kidney disease may occur in about 1% of children with impetigo. With the correct treatment, most patients recover from the disease without lasting effect.
The diagnosis of impetigo is clinical. This means that doctors can diagnose impetigo based only on its typical appearance. The characteristic changes in the skin are obvious and no investigations are usually needed.
- Once an infection has occurred, special care of the infected person and prompt treatment will prevent the disease from spreading.
- Avoid direct contact with the infected area.
- Good personal hygiene and a clean environment will prevent impetigo.
- Wash all sores and scratches with soap and water.
- Keep the area between a child’s upper lip and nose clean to prevent infection, especially if the child has a cold.
- Keep fingernails short and clean.
Regular washing with soap and water may clear up mild forms of impetigo.
For more serious cases, the following should supplement the doctor’s treatment:
- Remove the crusts by soaking the area in warm water for 15 or 20 minutes. Use a warm face-cloth for the face. Rub the area gently with the face-cloth and antibacterial soap. Gently pat the area dry. Repeat this treatment several times a day.
- Apply an antibiotic ointment such as Bactroban to the infected areas. Cover the infected areas with gauze taped well away from the sores. This will prevent the spread of the infection through touching and scratching.
- Apply the Bactroban antibiotic ointment three times a day.
- Do not share towels, face-cloths, or bath water. Men should not shave over the sores and should use a clean razor every day.
- Wash the towels and face-cloths that an infected person has used separately.
- The doctor may also prescribe antibacterial baths for the whole family to prevent household members from infecting one another.
A topical antibiotic ointment and/or an oral antibiotic such as penicillin or erythromycin are usually very effective in clearing the infection within a few days. Antibacterial ointments such as Bactroban are very effective if only a very small area is involved.
If the rash spreads and if a streptococcal (Strep) infection is suspected, children should always be treated with an oral antibiotic.
Penicillin and erythromycin are the usual antibiotics that are prescribed. The antibiotics are taken by mouth and will rapidly heal the impetigo rash. The antibiotics also protect children against the complications of severe infections such as nephritis and also shorten the healing time and reduce the chance of recurrence.
When treated and managed correctly, impetigo clears up without any complications within three to four days.
In severe cases the ulcerated form (ecthyma) may develop. If left untreated, this condition may cause scarring and pigment changes.
When to see your doctor
- If the impetigo covers an area larger than five centimetres in diameter.
- If there is no improvement after three to four days on treatment or if new areas of infection appear.
- If there is increased pain and warmth of the skin around the sores or swelling or redness or tenderness.
- If red streaks extend from the areas.
- If there is continued discharge of pus.
- If there is a fever of 37.8 º C or higher with no other obvious cause.
- If an impetigo rash occurs in a baby.
- If small, very itchy, pus-filled ulcers form, with a dark brown crust (symptoms of ecthyma).
- If a child with impetigo develops a headache, passes very little urine or has puffiness around the eyes and of the face and swelling of the feet or hands, these are symptoms of nephritis.
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Reviewed by Prof Eugene Weinberg, Paediatrician and Paediatric Allergist, Health24 expert, February 2015.