Herpes Zoster

Herpes zoster

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.

Treatments

Shingles almost always resolves spontaneously and may not require any treatment except for the relief of symptoms. In most people, the condition clears on its own in one or two weeks and seldom recurs. The antiviral drugs acyclovir, valacyclovir, and famciclovir can be used to treat shingles. These drugs may shorten the course of the illness. Their use results in more rapid healing of the blisters when drug therapy is started within 72 hours of the onset of the rash. In fact, the earlier the drugs are administered, the better, because early cases can sometimes be stopped. If taken later, these drugs are less effective but may still lessen the pain. Antiviral drug treatment does not seem to reduce the incidence of post-herpetic neuralgia, but recent studies suggest famciclovir may cut the duration of post-herpetic neuralgia in half. Side effects of typical oral doses of these antiviral drugs are minor with headache and nausea reported by 8-20% of patients. Severely immunocompromised individuals, such as those with cancer, may require intravenous administration of antiviral drugs. Preventive administration of acyclovir to seropositive patients (people who have evidence in their blood of past infection with varicella) who undergo leukemia induction or bone marrow transplant not only effectively prevents herpes zoster recurrence but also reduces the severity of chemotherapy-induced mucositis . Therefore, acyclovir prophylaxis should be considered in seropositive patients, especially if they have had a recurrence during previous chemotherapy cycles.

Alternative and complementary therapies

Cool, wet compresses may help reduce pain. If there are blisters or crusting, applying compresses made with diluted vinegar will make the patient more comfortable. The patient can mix one-quarter cup of white vinegar in two quarts of lukewarm water, and use the compress twice each day for 10 minutes. The patient should stop using the compresses when the blisters have dried up.

Soothing baths and lotions such as colloidal oatmeal baths, starch baths or lotions, and calamine lotion may help to relieve itching and discomfort. The skin should be kept clean, and contaminated items should not be re-used. While the lesions continue to ooze, the person should be isolated to prevent infecting other susceptible individuals.

Later, when the crusts and scabs are separating, the skin may become dry, tight, and cracked. If that happens, the patient can rub on a small amount of plain petroleum jelly three or four times a day.

There are non-medical methods of prevention and treatment that may speed recovery. For example, getting lots of rest, eating a healthy diet, exercising regularly, and minimizing stress are always helpful in preventing disease. Supplementation with vitamin B₁₂ during the first one to two days and continued supplementation with vitamin B complex, high levels of vitamin C with bioflavonoids, and calcium, are recommended to boost the immune system. Herbal antivirals such as echinacea can be effective in fighting infection and boosting the immune system. Patients should consult physician before taking supplements.

Although no single alternative approach, technique, or remedy has yet been proven to reduce the pain, there are a few options which may be helpful. For example, topical applications of lemon balm (Melissa officinalis ) or licorice (Glycyrrhiza glabra ) and peppermint (Mentha piperita ) may reduce pain and blistering. Homeopathic remedies include Rhus toxicodendron for blisters, Mezereum and Arsenicum album for pain, and Ranunculus for itching. Practitioners of Eastern medicine recommend self-hypnosis, acupressure, and acupuncture to alleviate pain. All of these or similar alternative therapies should be discussed with the treating physician before using.

See Also Antiviral therapy

Resources

BOOKS

Berger, Joseph. Cecil Textbook of Medicine, 21st Ed. Philadelphia: W.B. Saunders Company, 2000.

Lockie, Andrew. The Family Guide to Homeopathy: Symptoms and Natural Solutions. Prentice Hall Press, 1989.

Thomsen, Thomas Carl. Shingles. Cross River Press, 1990.

PERIODICALS

Balfour, Henry H. "Varicella Zoster Virus Infections in Immunocompromised Hosts." American Journal of Medicine 85 (29 August 1988): 68-72.

Bilgrami, S. et al. "Varicella zoster virus infection associated with high-dose chemotherapy and autologous stem-cell rescue." Bone Marrow Transplant 23 (March 1999): 469-74.

Kawasaki, H. et al. "Herpes zoster infection after bone marrow transplantation in children." Journal of Pediatrics 128 (March 1996):353-58.

Rusthoven, J. J. et al. "Varicella-zoster infection in adult cancer patients. A population study." Archives of Internal Medicine 148 (July 1988):1561-1566.

Perren, Timothy J., et al. "Prevention of Herpes Zoster in Patients by Long-Term Oral Acyclovir After Allogeneic Bone Marrow Transplantation." American Journal of Medicine 85 (29 August 1988): 99-101.

Wood, Martin J., et al. "Efficacy of Oral Acyclovir Treatment of Acute Herpes Zoster." American Journal of Medicine 85 (August 29, 1988): 79-83.

ORGANIZATION

American Academy of Dermatology. 930 N. Meacham Road, PO Box 4014, Schaumberg, IL 60168-4014. (708) 330-0230. http://www.aad.org. 29 June 2001.

David Greenberg, M.D.

KEY TERMS

Acyclovir

—An antiviral drug that is available under the trade name Zovirax, in oral, intravenous, and topical forms. The drug blocks the replication of the varicella zoster virus.

Antibody

—A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.

Famciclovir

—An oral antiviral drug that is available under the trade name Famvir. The drug blocks the replication of the varicella zoster virus.

Immunocompromised

—A state in which the immune system is suppressed or not functioning properly.

Post-herpetic neuralgia

—The term used to describe the pain after the rash associated with herpes zoster is gone.

Valacyclovir

—An oral antiviral drug that is available under the trade name Valtrex. The drug blocks the replication of the varicella zoster virus.