zóster

Zóster is a term used in medical contexts to refer to herpes zoster, the condition commonly known as shingles. It results from reactivation of latent varicella-zoster virus, the same virus that causes chickenpox, typically years after the initial infection.

Etymology and usage: The word zoster comes from Greek zoster, meaning belt or girdle, describing the characteristic band-like distribution of the rash. The diacritic form zóster appears in some language spellings or transliterations, but the underlying medical meaning remains the same.

Clinical presentation: The illness usually begins with pain, burning, or tingling in a localized area, followed by a unilateral vesicular rash distributed along a dermatome. The thoracic region is a common site, though involvement of the face or other areas can occur. Most cases heal within a few weeks, but some individuals experience ongoing nerve pain known as postherpetic neuralgia, especially with advancing age or severe initial pain. Complications can be more serious when the eye is affected or in immunocompromised individuals.

Diagnosis and treatment: Diagnosis is primarily clinical, supported by history and examination. Laboratory tests, such as PCR or direct fluorescent antibody testing, are used when the presentation is atypical. Antiviral medications (for example, acyclovir, valacyclovir, or famciclovir) are most effective when started within 72 hours of rash onset. Pain management, including analgesics and, in some cases, nerve-modulating medications, is commonly employed. Corticosteroids are not routinely recommended for uncomplicated cases.

Prevention and epidemiology: Vaccination reduces the risk and severity of zoster. The recombinant zoster vaccine (Shingrix) is recommended for adults 50 and older, typically in a two-dose schedule. The incidence rises with age, reinforcing the preventive role of vaccination in at-risk populations.

See also: shingles, varicella-zoster virus.