Herpes zoster

Basic information about the disease

The herpes zoster (łac. herpes zoster) is the reactivation (activation) of a latent virus infection caused by the varicella zoster virus and the herpes zoster virus (VZV, nowadays called human herpes virus – 3 – HHV-3), the same virus that causes varicella smallpox at the first infection. Thus, the disease can develop in all people who have had chickenpox in the past, regardless of whether the course of chickenpox was mild or severe. Herpes zoster is manifested by the unilateral appearance of painful, characteristically located vesicles on skin areas invaded by a single spine, called dermatoms. The appearance of skin changes is usually preceded by burning, itching, tingling sensations and pain that can persist throughout the disease. Herpes zoster is contagious to others. After contact with a patient, people exposed to the infection may get chickenpox.

How does the herpes zoster develop?

Herpes zoster

The cause of herpes zoster is the varicella virus and the herpes zoster virus (VZV), which causes varicella after initial infection. After healing from chickenpox, the VZV remains in the dorsal ganglia in a dormant inactive form, called the latency of the virus. Due to reasons that have not yet been fully discovered, most likely due to a decrease in specific cellular immunity, the VZV virus multiplies and reactivates many years later, which is clinically manifested by herpes zoster. The above-mentioned decrease in immunity may be the result of a gradual loss of immunity associated with age and time since the primary infection, associated diseases that adversely affect immunity or immunosuppressants.

What factors contribute to the onset of herpes zoster?

Herpes zoster may only occur in people who have previously been infected with varicella virus, more often due to natural infection, and who have contracted varicella or less often due to chickenpox vaccination. Age is a factor in the development of herpes zoster. The risk of herpes zoster increases rapidly after 50 years. After 85 years of age, the risk of herpes zoster is 50%. Similarly, along with age, the risk of postherpetic neuralgia increases dramatically. Therefore, elderly patients with herpes zoster may need hospitalization to treat complications of the disease, including neuralgia. Risk factors for herpes zoster include diseases that reduce cellular immunity, such as disseminated tumors, including leukaemia and lymphoma, infection with human immunodeficiency virus (HIV), and immunosuppressive therapy (glucocorticosteroids, drugs prescribed after organ transplantation). The severe course of herpes zoster is particularly prone to patients after bone marrow transplantation, as well as parenchymatous organs (kidneys, heart, liver and lungs) that take immunosuppressive therapy, including glucocorticosteroids. The risk factor is the treatment of cancer with radiotherapy or chemotherapy.

What is the risk of herpes zoster development?

Herpes zoster

According to current data from the United States, almost one in three people will develop a herpes zoster during their lifetime. Anyone with chickenpox, including children, may develop the disease, but the risk of the disease increases significantly with age. In practice, herpes zoster disease is an adult disease, and about half of all cases of herpes zoster develop after 60 years. As a rule, there is one episode of herpes zoster in life. In rare cases, especially if there are favorable factors, herpes zoster may occur two or more times.

Treatment of herpes zoster

Antiviral drugs are used in the treatment, which reduce the intensity and duration of symptoms of the disease. A prerequisite for efficacy is the early start of treatment, as soon as possible after the rash. Antiviral treatment has not been proven to prevent the most important complication – post-herpetic neuralgia. Pain manifestations are treated symptomatically.

Antiviral treatment

Anti-viral treatment reduces the intensity and duration of herpes zoster symptoms. Several antiviral drugs (acyclovir, valacyclovir, famcyclovir) are available that can reduce the duration and intensity. A prerequisite for effective treatment is its early onset – as soon as possible after a rash.