An infectious skin disease usually found in children where blisters appear (mostly on the face), burst, and form yellowish crusts. Impetigo is caused by infection from streptococcal and staphylococcal bacteria, which enter through cold sores, cuts, scratches, or other breaks in the skin. The disease is most often spread by direct contact with infected skin. For more information, visit The Impetigo Fact Sheet, Communicable Diseases: Impetigo, and The Group Health Cooperative's Impetigo Page.