What is herpes zoster?

In adults, herpes zoster can cause a lot of pain and even leave a sequel, postherpetic neuralgia, which causes fixed or intermittent pain accompanied by a sensitivity deficit of the affected nerve.

Shingle is an acute infection caused by the varicella-zoster virus (VZV), which mainly affects adults. It is characterized by the development of skin eruptions in the form of painful blisters or vesicles, which are located following the path of a nerve inflamed by the virus. Due to this particular disposition, the infection is popularly known as ‘ shingles. ‘ In some Mediterranean countries, it is also called the San Antonio fire.

This type of herpes is produced by the same virus as chickenpox, being a reactivation of this at the level of the nervous ganglia where it remains in a latent state to break into certain health circumstances in the form of herpes zoster.

This relationship has been known since 1892 where cases of chickenpox were observed after various contacts with people with shingles. Even though 95% of individuals at 18 years of age already have antibodies against the virus due to vaccination or infection caused by this virus, not everyone will develop neurocutaneous involvement. There must be a series of circumstances for this to occur (alterations of the immune system, either temporary or permanent due to some disease).

Initiating adequate antiviral treatment early reduces discomfort and avoids very painful complications.

Herpes zoster incidence and prognosis

Shingles affect around 20% of the population. It can occur at any age, although the most common is that it appears in people over 60 years of age or in people with a weakened immune system due to disease or medical treatment.

It is usually a benign process in children, but in the case of adults, it can become a very debilitating disease since it can cause great pain. In 4% of cases, the second outbreak of shingles reappears and up to 30% in HIV-infected cases.

It will be important to determine some hidden cause when a young adult develops this disease, for example, a study looking for malignant diseases or debilitating infections such as HIV infection.

The affectation in children under two years of age is believed to be the consequence of a chickenpox process in the mother during pregnancy, intrauterine infection by the virus. It should also be noted that the appearance of herpes zoster in the pregnant woman does not pose any particular risk to the fetus. However, it should not be treated with antivirals intended for this purpose except in very severe cases.

Herpes complications: postherpetic neuralgia

In general, it is a problem that usually persists for about a month until it disappears on its own, although measures can be established to treat the symptoms. However, in some immunosuppressed or elderly patients, complications may appear, such as postherpetic neuralgia, which can become disabling. If herpes affects the face, it can cause facial paralysis, eye problems, hearing problems, or encephalitis.

Main causes of shingles

The patient with herpes zoster is usually infected in childhood. At this first moment, an exanthematic disease develops (with reddish rashes on the skin) known as chickenpox, which constitutes the initial form of infection with the varicella-zoster virus. After chickenpox has resolved, the virus lies dormant for years in the patient’s dorsal nerves’ ganglia. The reactivation of this virus, which was inactivated, is the cause of shingles.

The two main factors why the latent chickenpox virus breaks out and manifests itself in the form of zoster are:

The functional alteration of immunity, the clear example being aging, where this system’s functioning and others is deteriorating.

The immune system’s pathological alteration due to medication (corticosteroids, chemotherapy), tumors, or infections such as HIV.

Transmission of the virus is likely to occur via the respiratory route. Chickenpox is an extremely contagious disease; the patient can contaminate other people from one day to five days after the blisters’ appearance. Even some babies whose mothers had chickenpox during pregnancy have developed shingles during the first two years of life.

Likewise, children who had chickenpox before reaching the first year of life have more ballots suffering from this problem.

It has also been observed that some medications, such as some of those used in the treatment of rheumatic diseases such as osteoarthritis, could favor their appearance.