Zoster

Zoster, also known as herpes zoster or shingles, is a viral disease caused by reactivation of the varicella zoster virus (VZV), a double-stranded DNA virus belonging to the herpesvirus family. The disease represents the reactivation of a latent infection that was initially acquired during childhood or adolescence as chickenpox (varicella). After the primary infection resolves, VZV persists in a dormant state within the dorsal root ganglia adjacent to the spinal cord or within the trigeminal ganglion at the base of the skull.

Zoster is characterized by a painful skin rash with blisters confined to a single dermatome, typically appearing as a unilateral band on either the left or right side of the body or face. Prodrome symptoms including tingling, burning pain, or local discomfort usually precede the rash by two to four days. Systemic symptoms such as fever, headache, and malaise may also occur. The rash typically heals within two to four weeks; however, some individuals develop postherpetic neuralgia, a chronic neuropathic pain condition that can persist for months or years. In immunocompromised patients, disseminated disease may occur with widespread lesions beyond the primary dermatome, potentially involving visceral organs such as the liver or brain. When the ophthalmic division of the trigeminal nerve is involved (zoster ophthalmicus), ocular complications including conjunctivitis, keratitis, uveitis, and vision loss may arise.

Zoster occurs exclusively in individuals previously infected with VZV and can manifest at any age, though incidence and severity increase with advancing age. Approximately half of reported cases in the United States occur in persons aged 50 years or older. Immunocompromised individuals face elevated risk for more severe disease manifestations, including disseminated zoster with potential organ involvement. Source-backed detail on geographic distribution patterns, seasonal variation, or global burden estimates is not yet available from the provided sources.

Zoster itself is not directly transmitted from person to person. However, the varicella zoster virus contained within the fluid of shingles blisters is infectious and can cause primary varicella (chickenpox) in individuals who have not previously been infected with VZV or received varicella vaccination. Such exposed individuals would develop chickenpox but would not develop zoster from that exposure. The virus does not spread via respiratory droplets.

Advanced age represents the primary risk factor for zoster development and for more severe disease manifestations. Immunocompromised individuals, including those with HIV/AIDS, hematologic malignancies, or those receiving immunosuppressive therapies, face elevated risk for disseminated disease and visceral complications. Individuals with poor immune function may develop widespread rash involving multiple dermatomes. Source-backed detail on additional risk factors or specific immunocompromising conditions is not yet available from the provided sources.

Public-health measures for zoster prevention center on vaccination strategies. Vaccination against VZV prevents primary varicella infection, thereby eliminating the reservoir for subsequent reactivation. Additionally, specific zoster vaccines are available for the prevention of herpes zoster and its complications in older adults. Source-backed detail on specific vaccine schedules, recommendations, or efficacy data is not yet available from the provided sources.

Zoster surveillance presents methodological challenges because diagnosis is primarily clinical, relying on recognition of the characteristic dermatomal rash pattern. Laboratory confirmation through VZV-specific IgM antibody detection is available but not always necessary for clinical management. The disease is coded under ICD-10 B02 and ICD-11 1E91. Surveillance data should account for the fact that many cases may not present for medical care, particularly in mild presentations, and that underreporting is likely. Age-specific incidence rates are particularly relevant given the strong association between advancing age and disease risk.

1. 1 Wikidata. herpes zoster.
2. 2 Wikipedia. Shingles - Wikipedia.

ICD-10

B02

ICD-11

1E91

Total cases

161K

Peak month

2019-10

Coverage

1 reporting countries · 2000-01-01 → 2026-05-01