Impetigo refers to a very localized bacterial infection of the skin. It tendsto afflict primarily children. Impetigo caused by the bacteria Staphylococcus aureus (or staph) affects children of all ages, while impetigo caused by the bacteria called group A. streptococci (or strep) are most common inchildren ages two to five.
The bacteria that cause impetigo are very contagious. They can be spread by scratching, or contact with a towel, clothing, or stuffed animal.
Impetigo tends to develop in areas of the skin that have already been damagedthrough some other mechanism (a cut, scrape, burn, insect bite, or pock from chicken pox).
There are two types of impetigo, bullous and epidemic. The first signof bullous impetigo is a large bump on the skin, with a clear, fluid-filled top (called a vesicle). The bump develops a scab-like, honey-colored crust. There is usually no redness or pain, although the area may be quite itchy. Ultimately, the skin in this area will become dry, and flake away. Bullous impetigo is usually caused by staph bacteria.
Epidemic impetigo can be caused by staph or strep bacteria, and (as the nameimplies) is very easily passed between children. Certain factors, such as heat and humidity, crowded conditions, and poor hygiene increase the chance thatthis type of impetigo will spread rapidly among large groups of children. Epidemic impetigo involves the formation of a small vesicle surrounded by a circle of reddened skin. The vesicles appear first on the face and legs. When achild has several of these vesicles close together, they may spread to each other. The skin surface may become eaten away (ulcerated), leaving irritated pits. When there are many of these deep, pitting ulcers, with pus in the center and brownish-black scabs, the condition is called ecthyma. If left untreated, the type of bacteria causing this type of impetigo has the potential to cause a serious kidney disease. Even when impetigo is initially caused by strepbacteria, the vesicles are frequently secondarily infected with staph bacteria.
Impetigo is usually an uncomplicated skin condition. Left untreated, however,there is a chance of developing a serious disease, including bone infection,joint infection, or pneumonia. If large quantities of bacteria are present and begin circulating in the bloodstream, the child is in danger of developing an overwhelming systemic infection known as sepsis.
Characteristic appearance of the skin is the usual method of diagnosis, although fluid from the vesicles can be cultured and then examined in an attempt to identify the causative bacteria.
Uncomplicated impetigo is usually treated with a topical antibiotic cream called mupirocin. In more serious, widespread cases of impetigo, or when the child has a fever or swollen glands, oral or intravenous antibiotics maybe given. The vast majority of children recover quickly, completely, and uneventfully.
Prevention involves good hygiene. Handwashing, never sharing towels, clothing, or stuffed animals, and keeping fingernails well-trimmed are easy precautions to take to avoid spreading the infection from one person to another.