Generalized rashes affect a large area and cover most of the body or several parts of the body. A generalized rash may be caused by an illness that affects another part of the body as well as the skin.

Common causes of a generalized rash are:

• Viruses, such as chickenpox or roseola. Viral illnesses that cause a rash are common in children.
• Common skin conditions, such as eczema or prickly heat.
• An allergic reaction to food, medicine, or other substances.

How a rash looks, how an illness develops, what other symptoms are present, and what illnesses are present in the community will help determine what treatment is needed.