Shingles Health Article

Definition

Shingles, also called herpes zoster, gets its name from both the Latin and French words for belt or girdle and refers to girdle-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 reemerge as shingles. Initially, red patches of rash develop into blisters. Because the virus travels along the nerve to the skin, it can damage the nerve and cause it to become inflamed. This condition can be very painful. If the pain persists long after the rash disappears, it is known as post-herpetic neuralgia.

Description

Any individual who has had chickenpox can develop shingles. Approximately 300,000 cases of shingles occur every year in the United States. Overall, approximately 20% of those who had chickenpox as children develop shingles at some time in their lives. People of all ages, even children, can be affected, but the incidence increases with age. Newborn infants, bone marrow and other transplant recipients, as well as indivduals with immune systems weakened by disease or drugs are also at increased risk. However, most individuals who develop shingles do not have any underlying malignancy or other immunosuppressive condition.

Causes and symptoms

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 lain 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, either as a result of stress, fatigue, certain medications, chemotherapy, or diseases, such as cancer or HIV. Further, it can be an early sign in persons with HIV that the immune system has deteriorated.

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

Diagnosis

Diagnosis is usually not possible until the skin lesions develop. Once they develop, however, the pattern and location of the blisters and the type of cell damage displayed are very characteristic of the disease, allowing an accurate diagnosis primarily based upon the physical examination.

Although tests are rarely necessary, they may include the following:

• viral culture of skin lesion
• microscopic examination using a Tzanck preparation, this involves staining a smear obtained from a blister, cells infected with the herpes virus will appear very large and contain many dark cell centers or nuclei
• complete blood count (CBC) may show an elevated white blood cell count (WBC), a nonspecific sign of infection
• rise in antibody to the virus

Treatment

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.

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. Mix one-quarter cup of white vinegar in two quarts of lukewarm water. Use the compress twice each day for 10 minutes. 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. Keep the skin clean, and do not re-use contaminated items. 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, rub on a small amount of plain petroleum jelly three or four times a day.

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 AIDS,may require intravenous administration of antiviral drugs.

Corticosteroids, such as prednisone, may be used to reduce inflammation but do interfere with the functioning of the immune system. Corticosteroids, in combination with antiviral therapy, also are used to treat severe infections, such as those affecting the eyes, and to reduce severe pain.

Once the blisters are healed, some people continue to experience pain for months or even years (post-herpetic neuralgia). This pain can be excruciating. Consequently, the doctor may prescribe tranquilizers, sedatives, or antidepressants to be taken at night. As noted above, attempts to treat post-herpetic neuralgia with the antiviral drug famciclovir have shown some promising results. When all else fails, severe pain may require a permanent nerve block.