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Impetigo

What is impetigo

If you have children, you've probably dealt with an assortment of rashes and skin irritations over the years. One of the most common of these is impetigo — a skin infection that usually appears on the face, especially around the nose and mouth. Although anyone can develop the infection, it mainly affects infants and young children.

Impetigo commonly occurs when bacteria enter the skin through cuts, scrapes or insect bites, but sometimes it affects perfectly healthy skin. It starts as a red sore that quickly ruptures, oozes for a few days and then forms a yellowish-brown crust that looks like honey or brown sugar. Impetigo is highly contagious, and scratching or touching the sores is likely to spread the infection to other parts of the body as well as to other people.

Impetigo is seldom serious, and minor infections may clear on their own in 2 to 3 weeks. But because impetigo can sometimes lead to complications, your child's doctor may choose to treat it with an antibiotic ointment or oral antibiotics. If so, healing should begin in about 3 days. Most often, your child can return to school or a child-care setting as soon as he or she isn't contagious — usually within 24 hours of starting antibiotic therapy.

You can help prevent impetigo by taking good care of your child's skin. When you bathe your child, use soap and water and pay special attention to cuts, rashes, insect bites and allergic reactions, such as those from poison oak or poison ivy. If anyone in your family does develop impetigo, a few simple measures can help keep the infection from spreading.


Children's Health Center

Signs and symptoms

Impetigo occurs in several types, each with its distinctive characteristics:

Impetigo contagiosa
The most common is impetigo contagiosa, which usually starts as a red sore on your child's face, most often around the nose and mouth. The sore ruptures quickly, oozing either fluid or pus that forms a honey-colored crust. Eventually the crust disappears, leaving a red mark that heals without scarring. The sores may be itchy, but they aren't painful.

Your child isn't likely to have a fever with this type of impetigo, but may have swollen lymph nodes in the affected area. And because the infection is extremely contagious, just touching or scratching the sores can cause it to spread to other parts of your child's body.

Bullous impetigo
Bullous impetigo primarily affects children younger than 2 years and infants. It causes painless blisters — usually on the trunk, arms and legs. The blisters may be large or small and may last longer than sores from other types of impetigo. Bullous impetigo may cause other signs and symptoms, including: Ecthyma
Ecthyma is a more serious form of impetigo in which the infection penetrates deep into the skin's second layer (dermis). Signs and symptoms include:
Fever
Diarrhea

Causes

Impetigo is usually caused by the bacterium Staphylococcus aureus, although another bacterium, Streptococcus pyogenes (Group A beta-hemolytic streptococcus), may also cause or contribute to the condition. Both types of bacteria can live harmlessly on your skin until they enter through a cut or other wound and cause an infection.

In adults, impetigo is usually the result of injury to the skin — often by another dermatological condition such as dermatitis. Children are commonly infected through a cut, scrape or insect bite, but they can also develop impetigo without having any damage to the skin. Impetigo that strikes healthy skin is called primary impetigo. Secondary impetigo occurs following an injury to your skin's protective barrier.

You're exposed to the bacteria that cause impetigo when you come into contact with the sores of someone who's infected or with items they've touched, such as clothing, bed linen, towels and even toys. Once you're infected, you can easily spread the infection yourself.

Staph bacteria produce a toxin that seems to make impetigo especially infectious. The toxin attacks a protein that helps bind skin cells together. Once this protein is damaged, germs can spread quickly.

Dermatitis

Risk factors

Although anyone can develop impetigo, children ages 2 to 6 years and infants are most likely to become infected. Children are especially susceptible to infections because their immune systems are still developing. And because staph and strep bacteria flourish wherever groups of people are in close contact, impetigo spreads easily in schools and child-care settings.

Other factors that increase the risk of impetigo include: Older adults and people with diabetes or a compromised immune system are especially likely to develop ecthyma, the most serious form of impetigo.

Diabetes

Screening and diagnosis

See your doctor if your child develops any unusual sores, especially if they contain fluid or pus. Although impetigo isn't dangerous, it may lead to serious complications when it's not treated or controlled.

Your pediatrician will usually diagnose the infection simply by looking at the lesions on your child's skin. But sometimes he or she may use a cotton swab to gently remove a small bit of material from one of the sores. This takes just a minute and shouldn't hurt. The material is then sent to a lab where it's grown on a special medium (culture) and checked for the presence of bacteria.

If you have a newborn with bullous impetigo, your baby is likely to be referred to a neonatologist for care.

Complications

Impetigo isn't dangerous, but sometimes it may lead to serious complications, including:
Strep throat
Kidney failure
High blood pressure
Meningitis
Cellulitis

Treatment

The treatments for impetigo may vary depending on your child's age, the type of impetigo and the severity of the infection. Treatments include:
Antibiotic-associated diarrhea

Prevention

Keeping your child's skin clean is the best way to keep it healthy. Bathe your child daily using soap and water, and treat cuts, scrapes, insect bites and other wounds right away to prevent infection. If someone in your family already has impetigo, follow these measures to help keep the infection from spreading to others:
Self-care

For minor infections that haven't spread to other areas, try the following: November 13, 2002