Shingles, medically referred to as herpes zoster, is caused by reactivation of the chickenpox virus. It usually occurs as burning or pain along one side of the body or face that progresses to grouped blisters on the skin. Shingles follows the distribution of nerves along the skin, thus most cases occur as stripes in the distribution of sensory skin nerves. Shingles may occur on the extremities, or in a severe, disseminated form where skin lesions are found all over the skin. Shingles occurs due to disturbances in the immune system. Increasing age, illness, malnutrition, and other health conditions increase the chances of shingles developing. Shingles is treated with oral antiviral medications. Sometimes pain must be controlled with other oral prescription medications. Patients with shingles should avoid contact with certain people with increased susceptibility (pregnant women, chemotherapy patients, HIV individuals) until they have been on successful treatment and the skin lesions have crusted over.