Herpes zoster (HZ) is a common disease; up to 1 in 3 people may develop it during their lifetime. It is a neurocutaneous manifestation caused by the opportunistic reactivation of the varicella-zoster virus, which remains latent in the cranial ganglia (a group of neuron bodies that are part of a nerve) or in the dorsal root (a bundle of nerve fibers that transmit sensory information from the body’s periphery to the spinal cord). About 90% of adults have been infected with the varicella virus and therefore could develop herpes zoster.

The main risk factor is age; incidence increases after age 50. Other predisposing factors include diseases that compromise the immune system, such as autoimmune disorders, cancer, AIDS, diabetes mellitus, COPD, asthma, COVID-19, among others.

The main symptom of HZ is intense pain, accompanied by the classic erythema with papules and vesicles, which is unilateral, does not cross the midline, and usually resolves within about a month. However, atypical forms can occur, such as pain without skin lesions (herpete) or bilateral involvement.

The most frequent complication is postherpetic neuralgia, which affects 5% to 30% of patients. It is characterized by pain in the affected area lasting more than 3 months. Treatment is complex and has limitations, which increases healthcare resource use and both direct and indirect costs. Other complications may include eye, ear, and central nervous system involvement, with encephalitis (inflammation of the brain), seizures, and significant brain damage.

Treatment of the acute infection is based on antivirals, which accelerate the resolution of skin lesions, reduce the formation of new ones, decrease viral spread, and lessen pain severity. Your doctor will select the antiviral based on the severity of the case, the need for intravenous treatment or not, dosage convenience, and antiviral potency. It is important to start treatment within 72 hours of lesion onset.

In addition to antivirals, glucocorticoids may be used under strict medical supervision to reduce pain intensity, accelerate healing, and help patients return to daily activities. They should never be administered without concurrent antiviral therapy. The third component of treatment is pain management (95% of patients experience pain), using potent analgesics and neuromodulators (gabapentin, pregabalin, antidepressants), all under medical supervision.

Vaccination is recommended to prevent reactivation of the latent virus. It is the only approved therapy to prevent the disease and its complications. The currently recommended vaccine is the recombinant HZ vaccine, which induces a strong and sustained immune response. It is recommended for adults aged 50 and older and has an efficacy rate of 97.2%. Vaccination after an acute infection should be given immediately after skin lesions have healed and can be safely co-administered, at a different anatomical site, with other vaccines (influenza, COVID-19, pneumococcal).