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Complications of Herpes Zoster

Herpes Zoster is caused by the same virus that causes chicken pox, Varicella zoster. Herpes Zoster infection is also known as shingles. Shingles occurs when a latent (or sleeping) viral infection is activated creating a localized rash on the skin. Shingles can be a very painful condition, but the outbreak only lasts for a short time (a few weeks). However, there are many complications that can arise from herpes zoster that can plague the patient for months or even years after the infection.

  1. Risk Factors

    • Although over 90 percent of all adults in the United States carry the Varicella zoster virus, those who are immunocompromised (the immune system is not functioning up to par due to another condition) or have a declining immune response as a result of aging are most susceptible to both the Herpes zoster infection and the complications it can cause. This includes patients who have certain cancers, those receiving certain drugs like corticosteroids and organ-transplant patients. In addition, those who are positive for human immunodeficiency virus (HIV) are also at a greater risk of developing complications. In fact, for patients under the age of 50 who have shingles with no apparent risk factors, an HIV test should be performed. Lastly, people over the age of 75 are at higher risk of experiencing complications from shingles.

    Postherpetic Neuralgia

    • The most common complication is postherpetic neuralgia, which is pain that exists for more than 30 days after the intial rash. The duration of this complication correlates to the age of the patient, meaning that the older the patient the longer the neuralgia will last. In addition to the pain, patients may experience other sensory abnormalities including sensitivity to touch in the area of the outbreak.

    Ocular Complications

    • Varicella zoster virus can lay dormant in the dorsal-root ganglia, which is in the nerves. When the virus is activated in certain nerves the result is ophthalmic zoster, which appears on the face. This form of the condition has a high rate of associated complications, with 50 to 90 percent of patients developing problems with their eyes. To reduce the risk of these complications patient should start antiviral therapy early in the outbreak.

    Contralateral Hemiparesis

    • A serious but rare complication of herpes zoster, especially the ophthalmic type, is contralateral hemiparesis, which is weakening of the side of the body opposite where the rash presented. This condition usually occurs weeks or even months after the rash has resolved. This weakening is due to a stroke caused by inflammation and therefore narrowing of the arteries in the brain due to the virus. Patients with contralateral hemiparesis have a 20 to 25 percent chance of death and those who live may have permanent neurologic damage.

    Encephalitis

    • Chronic Varicella zoster virus Encephalitis, inflammation of the brain due to a viral infection, is a rare but deadly complication of herpes zoster. This complication occurs exclusively in those patients with a suppressed immune system. The onset of the encephalitis is usually many months after the herpes zoster outbreak, making accurate diagnosis difficult. Although there may be some benefit to using a high-dose intravenous acyclovir (an anti-viral drug) therapy, most patients experience progressive deterioration which ends in death.

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