Impetigo

Definition:

A skin disorder characterized by crusting skin lesions, caused by bacterial infection.

Causes, incidence, and risk factors:

Impetigo is a common skin infection. It affects 1 out of 1,000 people. It is most common in children, particularly if they are exposed to poor hygienic conditions. In adults, it may follow other skin disorders. Impetigo may follow a recent upper respiratory infection such as a cold or other viral infection. It is similar to cellulitis, but more superficial, involving infection of the superficial skin (top layers) with streptococcus (strep), staphylococcus (staph), or both.

The skin normally has many types of bacteria on it, but intact skin is an effective barrier that keeps bacteria from entering and growing within the body. When there is a break in the skin, bacteria can enter the body and grow there, causing inflammation and infection. Breaks in the skin may occur with insect bites, animal bites, or human bites; or other injury or trauma to the skin. Impetigo may occur on skin where there is no visible break.

Impetigo begins as an itchy, red sore that blisters, oozes and finally becomes covered with a tightly adherent crust. It tends to grow and spread. Impetigo is contagious. The infection is carried in the fluid that oozes from the blisters. Rarely, impetigo may form deeper skin ulcers.