Herpes zoster: diagnostic, therapeutic, and preventive approaches

Herpes zoster (Hz), which generally presents as a localized, painful cutaneous eruption, is a common clinical problem, particularly among adults ≥ 50 years of age and immunocompromised patients. The diagnosis of Hz is mainly made clinically, except in patients with atypical manifestations or certain complications, such as central nervous system involvement, in which laboratory virologic testing is required. In addition to having a higher mortality rate, immunocompromised individuals have atypical and severe clinical findings and are at greater risk for complications and recurrence of Hz. Treatment of Hz includes the use of antiviral agents, analgesics for control of acute zoster pain, good skin care for healing, and prevention of secondary bacterial infection. Antiviral agents, preferably valacyclovir or famciclovir, should be started within 72 hours of onset to reduce the severity of the infection, the duration of the eruptive phase, and the intensity of acute pain. Herpes zoster has been associated with several complications, of which post-herpetic neuralgia (PHN) is the most common and debilitating. Varicella-zoster virus vaccine and early treatment with either famciclovir or valacyclovir are the only measures proven to prevent PHN. The options for treating PHN include topical agents, such as lidocaine patches, and systemic agents, such as the anticonvulsants gabapentin and pregabalin. Measures for preventing Hz include infection control through routine hand hygiene and appropriate use of isolation precautions and personal protective equipment; immunoglobulins, such as the varicella-zoster virus immunoglobulin and vaccine; and antiviral agents. The zoster vaccine has been shown to be effective in reducing the incidence of Hz and PHN. The vaccine is recommended for all individuals aged ≥ 60 years who have no contraindications, including individuals who report a previous episode of Hz.