Zoster in the elderly: clinical, immunologic and therapeutic considerations.

Herpes zoster is common in the elderly. Persons over the age of 50 years have an attack rate double that of patients less than 50 years old. In the very aged, this rate nearly doubles again. The loss of cell-mediated immunity for the VZ virus appears to be the primary factor in the disruption of the dynamic containment process responsible for VZ virus latency within the sensory ganglion. Humoral immunity may play a role in the maintenance of latency, but the degree is unproven, except in the case of dissemination where loss of detectable antibodies seems to correlate with extradermatomal dissemination. Severe forms of the disease and its complications, e.g., postherpetic neuralgia, are likely among the elderly. Direct immunofluorescent staining or cytologic examination is useful for early diagnosis, and serologic changes can document the confusing clinical entity of zoster sine herpete.