Impetigo  is a common and highly contagious skin infection that mainly affects infants and children. Impetigo usually appears as red sores on the face, especially around a child’s nose and mouth, and on hands and feet. The sores burst and develop honey-colored crusts.

Treatment with antibiotics is generally recommended to help prevent the spread of impetigo to others. It’s important to keep your child home from school or day care until he or she is no longer contagious — usually 24 hours after you begin antibiotic treatment.

Symptoms

Classic signs and symptoms of impetigo involve red sores that quickly rupture, ooze for a few days and then form a yellowish-brown crust. The sores usually occur around the nose and mouth but can be spread to other areas of the body by fingers, clothing and towels. Itching and soreness are generally mild.

A less common form of the disorder, called bullous impetigo, may feature larger blisters that occur on the trunk of infants and young children.

A more serious form of impetigo, called ecthyma, penetrates deeper into the skin — causing painful fluid- or pus-filled sores that turn into deep ulcers.

Causes

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.

Risk factors

Factors that increase the risk of impetigo include:

• Age. Impetigo most commonly occurs in children ages 2 to 5.
• Crowded conditions. Impetigo spreads easily in schools and child care settings.
• Warm, humid weather. Impetigo infections are more common in summer.
• Certain sports. Participation in sports that involve skin-to-skin contact, such as football or wrestling, increases your risk of developing impetigo.
• Broken skin. The bacteria that cause impetigo often enter your skin through a small skin injury, insect bite or rash.

Adults and people with diabetes or a weakened immune system are more likely to develop ecthyma.

Complications

Impetigo typically isn’t dangerous. And the sores in mild forms of the infection generally heal without scarring.

Rarely, complications of impetigo include:

• Cellulitis. This potentially serious infection affects the tissues underlying your skin and eventually may spread to your lymph nodes and bloodstream. Untreated cellulitis can quickly become life-threatening.
• Kidney problems. One of the types of bacteria that cause impetigo can also damage your kidneys.
• Scarring. The ulcers associated with ecthyma can leave scars.

Prevention

Keeping skin clean is the best way to keep it healthy. It’s important to wash cuts, scrapes, insect bites and other wounds right away.

To help prevent impetigo from spreading to others:

• Gently wash the affected areas with mild soap and running water and then cover lightly with gauze.
• Wash an infected person’s clothes, linens and towels every day and don’t share them with anyone else in your family.
• Wear gloves when applying antibiotic ointment and wash your hands thoroughly afterward.
• Cut an infected child’s nails short to prevent damage from scratching.
• Wash hands frequently.
• Keep your child home until your doctor says he or she isn’t contagious.

Diagnosis

Doctors usually diagnose impetigo by looking at the distinctive sores. Lab tests generally aren’t necessary.

If the sores don’t clear, even with antibiotic treatment, your doctor may take a sample of the liquid produced by a sore and test it to see what types of antibiotics might work best on it. Some types of the bacteria that cause impetigo have become resistant to certain antibiotic drugs.

Treatment

Impetigo typically is treated with an antibiotic ointment or cream that you apply directly to the sores. You may need to first soak the affected area in warm water or use wet compresses to help remove the scabs so the antibiotic can penetrate the skin.

If you have more than just a few impetigo sores, your doctor might recommend antibiotic drugs that can be taken by mouth. Be sure to finish the entire course of medication even if the sores are healed. This helps prevent the infection from recurring and makes antibiotic resistance less likely.