Shingles (herpes zoster) and postherpetic neuralgia, a chronic neuropathic pain syndrome that can persist after the shingles lesions heal, were studied by eminent neurologists of the 19th century. Autopsy studies were used to establish sensory neural pathways in the peripheral and central nervous systems. More recently, zoster and postherpetic neuralgia have served as models for the study of the pathogenesis and treatment of neuropathic pain. Postherpetic neuralgia has the cardinal clinical features of all neuropathic pain syndromes, including sensory abnormalities, ongoing pain, and allodynia (touch-induced pain). Unlike most other neuropathic pain syndromes, such as trigeminal neuralgia or nerve root compressions, shingles has a well-defined pathogenesis and onset, as well as visible lesions, and is therefore uniquely suitable for study.