Impetigo is a highly contagious skin infection that mainly affects children. It is most likely to occur in a warm and humid environment and spreads by close contact. It usually appears as red sores and fluid-filled blisters. The blisters rupture leaving a rash that becomes a yellow crust. The most common areas for the sores to appear are around the mouth and nose but it can be spread to other areas of the body. In order to recommend the right treatment dermatologist look at different factors including the severity.