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 1% 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. Beta hemolytic streptococcus is another bacteria that causes it. These bacteria lurk everywhere -- in unclean bathrooms, in spoiled food, and in our own bodies. If a child with an open wound or fresh scratch bathes in an unscrubbed basin or tub, for example, 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.

Call Your Doctor If:

NOTE: Sores associated with impetigo may be mistaken for herpes, a viral infection. Impetigo spreads faster, never develops inside the mouth, and is rarely confined to one area of the body. If in doubt, see a doctor for an accurate diagnosis.

The key to treating -- and preventing -- impetigo is good personal hygiene and a clean environment. Once the infection occurs, prompt attention will keep it under control and prevent its spread.

Even if only one family member has impetigo, everyone in the household should follow the same sanitary regimen. Regular washing with soap and water can clear up mild forms. If the sores don't clear up in 48 hours, or if the infected person is a small child, see a doctor. To break the chain of contagion, the doctor may prescribe antibacterial baths for the entire household as well as for the infected patient.

A topical mupirocin ointment, available only by prescription, is highly successful in treating routine cases. Don't try over-the-counter antibacterial ointments; they are too weak to kill strep and staph infections, and applying the ointment carelessly may actually spread the impetigo. If mupirocin does not help in 48 hours, ask your doctor about an oral antibiotic such as Keflex or Zithromax.

If you have only a few small impetigo sores, simply bathing them regularly with soap and warm water, using the medications mentioned above, and exposing them to air will soothe the itchiness and should clear them up. For more severe cases, wash the infected area with antibacterial soap and follow up with an appropriate medical treatment.

Anyone in a household who develops impetigo should use a clean towel with each washing. Be sure to launder those towels separately.