Eruption of grouped vesicles on an erythematous base usually limited to a single dermatome (“shingles”); disseminated lesions can also occur, especially in immunocompromised pts (See Also Chap. 99. Herpesvirus Infections). Tzanck preparation reveals multinucleated giant cells; indistinguishable from herpes simplex except by culture. Detection of varicella zoster virus DNA by PCR is confirmatory but of limited availability. Postherpetic neuralgia, lasting months to years, may occur, especially in the elderly.