Herpes zoster represents a reactivation of VZV from dorsal root ganglia and usually manifests as a unilateral vesicular eruption within a dermatome, often associated with severe pain.

• Dermatomal pain may precede lesions by 48-72 h, and dermatomes T3 to L3 are most frequently involved.
• The usual duration of disease is 7-10 days, but it may take as long as 2-4 weeks for the skin to return to normal.
• With ~1.2 million cases each year in the United States, the incidence is highest among pts ≥50 years of age.
• Pts with herpes zoster can transmit infection to seronegative individuals, with consequent chickenpox.
• Complications include zoster ophthalmicus (which can lead to blindness), Ramsay Hunt syndrome (characterized by pain and vesicles in the external auditory canal, loss of taste in the anterior two-thirds of the tongue, and ipsilateral facial palsy), and postherpetic neuralgia (pain persisting for months after resolution of cutaneous disease).
• Immunocompromised pts—particularly those with Hodgkin's disease and non-Hodgkin's lymphoma—are at greatest risk for severe zoster and progressive disease. Cutaneous dissemination occurs in 40% of these pts and increases the risk for other complications (pneumonitis, meningoencephalitis, hepatitis).