Herpes zoster is infection that results when varicella-zoster virus reactivates from its latent state in a posterior dorsal root ganglion. Symptoms usually begin with pain along the affected dermatome, followed within 2 to 3 days by a vesicular eruption that is usually diagnostic. Treatment is with antiviral medications, ideally given within 72 hours after skin lesions appear.
(See Overview of Herpesvirus Infections.)
Chickenpox and herpes zoster are caused by the varicella-zoster virus (human herpesvirus type 3); chickenpox is the acute, primary infection phase of the virus, and herpes zoster (shingles) represents reactivation of virus from the latent phase.
Herpes zoster inflames the sensory root ganglia, the skin of the associated dermatome, and sometimes the posterior and anterior horns of the gray matter, meninges, and dorsal and ventral roots. Herpes zoster frequently occurs in older adults and people living with HIV and is more frequent and severe in patients who are immunocompromised because cell-mediated immunity in these patients is decreased. There are no clear-cut precipitants.
Symptoms and Signs of Herpes Zoster
Lancinating, dysesthetic, or other pain develops in the involved site, typically followed within 2 to 3 days by a rash, usually crops of vesicles on an erythematous base. The site is usually one or more adjacent dermatomes in the thoracic or lumbar region, although a few satellite lesions may also appear. Lesions are typically unilateral and do not cross the midline of the body. The site is usually hyperesthetic, and pain may be severe. Lesions usually continue to form for about 3 to 5 days.
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Herpes zoster may disseminate to other regions of the skin and to visceral organs, especially in patients who are immunocompromised.
Geniculate zoster (Ramsay Hunt syndrome, herpes zoster oticus) results from involvement of the geniculate ganglion. Ear pain, facial paralysis, and sometimes vertigo occur. Vesicles erupt in the external auditory canal, and taste may be lost in the anterior two thirds of the tongue.
Ophthalmic herpes zoster results from involvement of the gasserian ganglion, with pain and vesicular eruption around the eye and on the forehead, in the V1 distribution of the ophthalmic division of the 5th (trigeminal) cranial nerve. Ocular disease can be severe. Vesicles on the tip of the nose (Hutchinson sign) indicate involvement of the nasociliary branch and a higher risk of severe ocular disease. However, the eye may be involved in the absence of lesions on the tip of the nose. An ophthalmology consultation should be sought in V1 distribution zoster.
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© Springer Science+Business Media
Intraoral zoster is uncommon but may produce a sharp unilateral distribution of lesions. No intraoral prodromal symptoms occur.
Symptoms and signs reference
1. Yawn BP, Wollan PC, Kurland MJ, St Sauver JL, Saddier P. Herpes zoster recurrences more frequent than previously reported. Mayo Clin Proc 86(2):88-93, 2011. doi:10.4065/mcp.2010.0618
Postherpetic neuralgia
Up to 6% of patients with herpes zoster experience another outbreak (1), although this percentage may be higher in immunocompromised hosts. However, many patients, particularly older patients, have localized pain with variable intensity lasting > 3 months from the last crusted lesion in the involved distribution (postherpetic neuralgia).
Pearls & Pitfalls
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The pain of postherpetic neuralgia may be sharp and intermittent or constant and may be debilitating. It may persist for months or years or permanently.
Diagnosis of Herpes Zoster
History and physical examination
Herpes zoster is suspected in patients with the characteristic rash and sometimes even before the rash appears if patients have typical pain in a dermatomal distribution. Diagnosis is usually based on the virtually pathognomonic rash.
If the diagnosis is equivocal, detecting multinucleate giant cells with a Tzanck test can confirm infection, but the Tzanck test is positive with herpes zoster or herpes simplex. Herpes simplex virus (HSV) may cause nearly identical lesions, but unlike herpes zoster, HSV tends to recur and is not dermatomal. Viruses can be differentiated by culture or polymerase chain reaction (PCR). Antigen detection from a biopsy sample can also be used to detect herpes zoster.
Treatment of Herpes Zoster
Symptomatic treatment
Wet compresses are soothing, but systemic analgesics are often necessary.
For treatment of ophthalmic herpes zoster, an ophthalmologist should be consulted. For treatment of otic herpes zoster, an otolaryngologist should be consulted.
Antiviral therapy
Treatment with oral antivirals decreases the severity and duration of the acute eruption and decreases the rate of serious complications in patients who are immunocompromised; it may decrease the incidence of postherpetic neuralgia. In patients who are immunocompetent, antiviral therapy is often reserved for those who are ≥ 50 years in whom benefit is greatest. Treatment is also indicated in patients with severe pain, facial rash especially around the eye, and in patients who are immunocompromised.
Treatment of herpes zoster should start as soon as possible, ideally during the prodrome, and is less likely to be effective if given >
Management of postherpetic neuralgia
Prevention of Herpes Zoster
A Recommendations of the Advisory Committee on Immunization Practices for Use of Herpes Zoster VaccinesUse of Recombinant Zoster Vaccine in Immunocompromised Adults Aged ≥ 19 Years: Recommendations of the Advisory Committee on Immunization Practices-Unites States, 2022).
A postmarketing observational study observed an increased risk of Guillain-Barré syndromeFDA Requires a Warning about Guillain-Barré Syndrome (GBS) be Included in the Prescribing Information for Shingrix).
1). The live-attenuated vaccine is contraindicated in patients who are immunocompromised.
Prevention reference
1. Lal H, Cunningham AL, Godeaux O, et al: Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med 372(22):2087-96, 2015. Epub 2015 Apr 28. PMID: 25916341. doi: 10.1056/NEJMoa1501184
Key Points
Herpes zoster is caused by reactivation of the varicella-zoster virus (the cause of chickenpox) from its latent phase.
A painful rash, usually crops of vesicles on an erythematous base, develops on one or more adjacent dermatomes.
Fewer than 4% of patients have another outbreak of zoster, but many, particularly older patients, have persistent or recurrent pain for months or years (postherpetic neuralgia).
Analgesics are often necessary.
Adults ≥
More Information
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