Herpes Zoster Health Article

Description

Herpes zoster, also called shingles, and referred to as "zosteer", gets its name from both the Latin and French words for belt or girdle and refers to belt-like skin eruptions that may occur on the trunk of the body. The virus that causes chickenpox, the varicella zoster virus (VSV), can become dormant in nerve cells after an episode of chickenpox and later re-emerge as shingles. Any individual who has had chickenpox can develop shingles. People of all ages, even children, can be affected, but the incidence increases with age. There are many other conditions which can predispose to developing shingles. These include: newborn infants, bone marrow and other transplant recipients, and individuals with immune systems weakened by diseases like HIV or cancer, or drugs, such as those used in chemotherapy.

Shingles erupts along the course of the affected nerve, producing lesions anywhere on the body and may cause severe nerve pain. The most common areas to be affected are the face and trunk, which correspond to the areas where the chickenpox rash is most concentrated. The disease is caused by a reactivation of the chickenpox virus that has been dormant in certain nerves following an episode of chickenpox. Exactly how or why this reactivation occurs is not clear; however, it is believed that the reactivation is triggered when the immune system becomes weakened as in the examples described above. Early signs of shingles are often vague and can easily be mistaken for other illnesses. The condition may begin with fever and malaise (a vague feeling of weakness or discomfort). Within two to four days, severe pain, itching, and numbness/tingling (paresthesia) or extreme sensitivity to touch (hyperesthesia) can develop, usually on the trunk and occasionally on the arms and legs. Pain may be continuous or intermittent, usually lasting from one to four weeks. It may occur at the time of the eruption, but can precede the eruption by days, occasionally making the diagnosis difficult. Signs and symptoms may include the following:

• itching, tingling, or severe burning pain
• red patches that develop into blisters
• grouped, dense, deep, small blisters that ooze and crust
• swollen lymph nodes

Immunocompromised patients usually have a more severe course that is frequently prolonged for weeks to months. They develop shingles frequently and the infection can spread to the skin, lungs, liver, gastrointestinal tract, brain, or other vital organs.

Potentially serious complications can result from herpes zoster. Many individuals continue to experience persistent pain long after the blisters heal. This pain, called post-herpatic neuralgia, can be severe and debilitating. Post-herpetic neuralgia can persist for months or years after the lesions have disappeared.

Other complications include a secondary bacterial infection, and rarely, potentially fatal inflammation of the brain (encephalitis) and the spread of an infection throughout the body. These rare, but extremely serious, complications are more likely to occur in those individuals who have weakened immune systems (immunocompromised).

Causes

Herpes zoster has been reported in patients with many different types of cancer. However, the cancers that affect an individual's immune system, such as leukemia or lymphoma, are the types that place people at particular risk. Herpes zoster is also a particular problem after the various forms of cancer therapy. A study performed in 1998 looked at 766 episodes of herpes zoster infection at a large cancer center from 1972 to 1980. The highest risk of infection was present among patients with lymphoma and leukemia. In those who received radiation treatment and then developed herpes zoster, half of them developed this within seven months. They developed zoster on the area of their body where the radiation was given. This study showed that a period of months can pass before developing zoster as a consequence of radiation. In those who developed zoster after being treated with chemotherapy, half of them developed zoster within a month.

A study in 1999 looked at 215 consecutive patients who had received high-dose chemotherapy and autologous stem cell rescue to help determine what the incidence and severity of herpes zoster infection was. Herpes zoster was developed in 40 people. Over 80% of these infections occurred within six months of receiving the autologous stem cell rescue. Similar rates of herpes zoster have been seen in patients who received bone marrow transplants. A 1996 study looked at 107 children who had received bone marrow transplants for various malignancies. Thirty-three percent of these children developed herpes zoster. Approximately 90% of the cases developed within one year from the time of bone marrow transplant.