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What Is Impetigo?

Impetigo is a highly contagious bacterial skin infection. It can appear anywhere on the body but usually attacks exposed areas. Children tend to get it on the face, especially around the nose and mouth, and sometimes on the arms or legs. The infected areas appear in patches ranging from dime to quarter size, starting as tiny blisters that break and expose moist, red skin. After a few days the infected area is covered with a grainy, golden crust that gradually spreads at the edges.

In extreme cases, the infection invades a deeper layer of skin and develops into ecthyma, an ulcerated form of the disease. Ecthyma forms small, pus-filled ulcers with a crust much darker and thicker than that of ordinary impetigo. Ecthyma can be very itchy, and scratching the irritated area spreads the infection quickly. Left untreated, the ulcers may cause permanent scars and pigment changes.

The gravest potential complication of impetigo is glomerulonephritis, a severe kidney disease that occurs in about 2 to 5% of cases, mainly in children. With antibiotic treatment and dietary restrictions, most patients recover from this disease without lasting effect.

The most common cause of impetigo is Staphylococcus aureus. However, another bacteria source is Beta hemolytic streptococcus. These bacteria lurk everywhere -- in unclean bathrooms, in spoiled food, and even in our own bodies. For example, if a child with an open wound or fresh scratch bathes in an unscrubbed basin or tub, he or she may contract impetigo. Using a towel or even a bar of soap previously used by a person infected with impetigo can spread the infection. Other skin-related problems, such as body lice, insect bites, fungal or bacterial infections, boils or various forms of dermatitis, can make a person susceptible to impetigo.

Most people get this highly infectious disease through physical contact with someone who has it, or from sharing the same clothes, bedding, towels, or other objects. The very nature of childhood, which includes lots of physical contact and large-group activities, makes children the primary victims and carriers of impetigo. Excessive sweating, malnutrition and poor hygiene can aggravate the condition.