Herpes Zoster (Shingles)

Also called shingles, herpes zoster is an acute unilateral and segmental inflammation of the dorsal root ganglia caused by infection with the herpesvirus varicella-zoster, which also causes chickenpox. This infection usually occurs in adults. It produces localized vesicular skin lesions confined to a dermatome and severe neuralgic pain in peripheral areas innervated by the nerves arising in the inflamed root ganglia.

The prognosis is good unless the infection spreads to the brain. Eventually, most patients recover completely, except for possible scarring and, in corneal damage, visual impairment. Occasionally, neuralgia may persist for months or years.

Causes

Herpes zoster results from reactivation of varicella virus that has lain dormant in the cerebral ganglia (extramedullary ganglia of the cranial nerves) or the ganglia of posterior nerve roots since a previous episode of chickenpox.

Exactly how or why this reactivation occurs isn't clear. Some believe that the virus multiplies as it is reactivated and that it is neutralized by antibodies remaining from the initial infection. But if effective antibodies aren't present, the virus continues to multiply in the ganglia, destroy the host neuron, and spread down the sensory nerves to the skin.

Signs and symptoms

Herpes zoster usually runs a typical course with classic signs and symptoms.

• First, there may be burning, itching, tingling, or extreme sensitivity in one area of the skin usually limited to one side of the body. This may be present for one to three days before a red rash appears at that site.
• The rash of shingles begins as red patches that soon develop blisters, often on one side of the body. The blisters may remain small or can become large. They heal in two to four weeks. They may leave scars.
• Grouped, dense, deep, small blisters that ooze and crust
• Shingles is often painful, this is because the virus travels along the nerve to get to the skin resulting in inflammation and damage to the nerve.

Diagnosis

he diagnosis is based on the way the blisters look and a history of pain before the rash on one side of the body. The dermatologist may scrape skin cells from a blister onto a glass slide for examination under a microscope. Also, the blister fluid containing the virus can be sent to the laboratory for special testing.

If someone has zoster, is there any reason to worry about a more serious disease or a poorly functioning immune system?

Most people with zoster are healthy. However, sick people or those with HIV are at risk, and this affects treatment. A chest x-ray or blood studies may be done.

Treatment

No specific treatment exists. The primary goal of herpes zoster treatment is to relieve itching and neuralgic pain with calamine lotion or another antipruritic; aspirin, possibly with codeine or another analgesic; and, occasionally, collodion or tincture of benzoin applied to unbroken lesions.

If bacteria have infected ruptured vesicles, treatment usually includes an appropriate systemic antibiotic. Trigeminal zoster with corneal involvement calls for instillation of idoxuridine ointment or another antiviral agent.

To help a patient cope with the intractable pain of postherpetic neuralgia, administer a systemic corticosteroid, such as cortisone or, possibly, corticotropin, to reduce inflammation as well as tranquilizers, sedatives, or tricyclic antidepressants with phenothiazines.

Acyclovir seems to stop progression of the rash and prevent visceral complications. In immunocompromised patients-both children and adults-acyclovir therapy may be administered I. V. The drug appears to prevent disseminated, life-threatening disease in some patients.

Treat your rash gently. Don't open your blisters. As long as there is blistering or crusting, compresses with dilute vinegar will make you more comfortable. Compress the blisters or crusts for 10 minutes twice daily with a mixture of one-quarter cup of white vinegar and two quarts of lukewarm water. Stop the compresses when the blisters have dried up.

Prevention

Prevention is uncertain. Avoid contact with the skin lesions of persons with known herpes zoster infection (shingles or chickenpox) if you have never had chickenpox or the chickenpox vaccine, or ESPECIALLY if your immune system is compromised.

The chickenpox vaccine (varicella) is a recommended childhood vaccine. The vaccine may be recommended for teenagers or adults who have never had chickenpox.