A localized rash affects only a small area or is limited to one part of the body. The appearance of a rash may give clues about what is causing it and how severe it is.

Most localized rashes are caused by minor problems, such as:

• Dry skin.
• Impetigo.
• Heat rash (prickly heat).
• Cold sores.
• Contact dermatitis.

Localized rashes will usually get better and go away with home treatment.

Serious localized rashes rarely appear without other symptoms, such as pain or fever. It is important to determine whether other symptoms are present and evaluate those symptoms.

Localized rashes that may require a visit to a health professional include:

• Lyme disease. Lyme disease is caused by a bacteria carried by deer ticks in some areas. A characteristic expanding red rash usually occurs at the site of the tick bite and is followed by flulike symptoms, such as a headache, chills, fever, body aches, and stiffness.
• Diaper rashes. Diaper rashes are caused by irritation of the skin from moisture, chemicals, or bacteria in the baby's urine or stool or from substances in disposable diapers.