Impetigo

A contagious, superficial skin infection, impetigo (also known as impetigo contagiosa) occurs in non bullous and bullous forms. This vesiculopustular eruptive disorder spreads most easily among infants, young children, and elderly people.

Predisposing factors such as poor hygiene, anemia, malnutrition, and a warm climate favor outbreaks of this infection, most of which occur during the late summer and early fall. Impetigo can complicate chickenpox, eczema, and other skin conditions marked by open lesions.

Causes

Impetigo can be caused by the Staphylococcus aureus (staph) or group A Streptococci (strep) bacteria. Bullous impetigo is usually caused by the staph bacteria and can occur at any age, while impetigo caused by strep is more likely to appear between the ages of two and five. Impetigo is extremely contagious. It can be spread by direct contact with the infected skin or through contact with an item used by the infected person. Epidemic impetigo spreads quickly among children and is aided by poor hygiene, overcrowded living conditions, and heat. Staph and strep bacteria can get through the skin's natural defenses if the skin is broken, such as by a cut, bite, or chickenpox sores.

Signs and symptoms

Common nonbullous impetigo typically begins with a small red macule that turns into a vesicle, becoming pustular with a honey-colored crust within hours. When the vesicle breaks, a thick yellow crust forms from the exudate. Autoinoculation may cause satellite lesions. Other features include pruritus, burning, and regional lymphadenopathy.

A rare but serious complication of streptococcal impetigo is glomerulonephritis.

In bullous impetigo, a thin-walled vesicle opens and a thin, clear crust forms on the subsequent eruption. It commonly appears on exposed areas.

Diagnosis

Impetigo is usually diagnosed based on a complete medical history and physical examination of your child. The lesions of impetigo are unique, and usually allow for a diagnosis based simply on physical examination. In addition, your child's physician may order a culture of your child's lesion to confirm the diagnosis and the type of bacteria that is present.

Treatment

Generally, treatment consists of systemic antibiotics (usually a pencillinase-resistant penicillin, cephalosporin, or erythromycin) for 10 days. A topical antibiotic such as mupirocin ointment may be used for minor infections.

Therapy also includes removal of the exudate by washing the lesions two or three times a day with soap and water or, for stubborn crusts, using warm soaks or compresses of normal saline or a diluted soap solution.

Contagiousness

Impetigo may itch and can be spread by scratching. Kids can spread the infection by scratching it and then touching other parts of the body.

Impetigo is contagious and can spread to anyone who comes into contact with infected skin or other items, such as clothing, towels, and bed linens, that have been touched by infected skin.

Prevention

Good general health and hygiene help to prevent infection. Minor abrasions or areas of damaged skin should be thoroughly cleansed with soap and clean water. A mild antibacterial agent may be applied if desired.

Make sure that anyone in your family with impetigo keeps his or her fingernails cut short and that the impetigo sores are covered with gauze and tape.