Herpes Zoster, also known as shingles or zoster, is a viral infection caused by the same virus that causes chicken pox. Anyone who has had chicken pox can develop herpes zoster. The virus remains dormant to inactive in certain nerve root cells of the body and only when it reactivates does zoster occur. About 20 percent of those people who have had chicken pox will get zoster at some time during their lives. Fortunately, most people will get zoster only once.
It is not clear what prompts the virus to reactivate or “awaken” in healthy people. A temporary weakness in immunity (the body’s ability to fight infection) may allow the virus to multiply and move along nerve fibers toward the skin. Although children can get zoster, it is more common in people over the age 50. Illness, trauma and stress may also trigger a zoster attack.
People with a weakened immunity for any reason are more prone to develop zoster. They are also more likely to have a serious form of it. Diseases that weaken immunity include cancers, such as leukemia or lymphoma, and AIDS. Some medical treatments including chemotherapy or radiation for cancer, drugs taken to prevent rejection of transplanted organs, and cortisone pills or injections taken for a long time, may also lower immunity.
What are the symptoms of zoster?
The first symptom of zoster is burning pain, 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. There may also be fever or headache. The rash soon turns into groups of blisters that look a lot like chicken pox. The blisters generally last for two to three weeks. The bl isters start out clear but then pus or dark blood collects in the blisters before they crust over (scab) and begin to disappear. The pain may last longer. It is unusual but possible to have pain without blisters or blisters without pain.
How severe is the pain?
The pain IS often severe enough for the physician to prescribe painkillers.
Where does zoster usually appear on the body?
Zoster is most common on the trunk and buttocks. But it can also appear on the face, arms or legs if nerves in these areas are involved.
Great care is needed if the blisters involve the eye because permanent eye damage can result. Blisters on the tip of the nose signal possible eye involvement. The dermatologist will usually refer the patient to an ophthalmologist (eye specialist) immediately.
What are the complications of zoster?
Post-herpetic neuralgia is constant pain or periods of pain that can continue after the skin bas healed. It can last for months or even years and is more common in older people. The use of medication in the early stages of the zoster may help prevent this complication.
A bacterial infection of the blisters can occur, and can delay healing. If pain and redness increase or reappear, you should return to the dermatologist. Antibiotic treatment may be needed.
Another complication is the spread of zoster allover the body or to internal organs. This can also happen with chicken pox. It occurs rarely and most often in those with weakened immunity.
How is zoster diagnosed?
The 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. The glass slide is then examined under a microscope for changes characteristic of zoster. If there is any doubt, blister fluid containing 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?
The majority of people who develop zoster are otherwise healthy; however, if you have other medical problems or could have been exposed to the AIDS virus, be sure to let your dermatologist know. This could affect treatment. Your doctor will ask questions about your medical history and may order tests, such as chest x-ray or blood studies, to be sure there are no other problems.
Is zoster contagious?
The virus that causes zoster can only be passed on to others who have not had chicken pox and then they will develop chicken pox, not zoster. Zoster is much less contagious than chicken pox. Persons with zoster can only transmit the virus if blisters are broken. Newborns or those with decreased immunity are at the highest risk for contracting chicken pox from someone who has zoster. Patients with zoster rarely require hospitalization.
Is there much scarring?
Scarring usually occurs only after more severe infections, such as in those with weakened immune systems, elderly persons or those whose blisters become infected.
What about treatment?
Zoster, usually clears on its own in a few weeks and seldom recurs. Pain relievers and cool compresses are helpful in drying the blisters.
If diagnosed early, oral anti-viral drugs can be prescribed to decrease both viral shedding and the duration of skin lesions. They are routinely prescribed for severe cases of zoster – with eye involvement, for example or for those with decreased immunity.
These drugs occasionally cause headache, stomach upset or lightheadedness. The earlier treatment is started the better. These drugs do not seem to prevent post-herpetic neuralgia, but may shorten its duration.
Corticosteroids, sometimes in combination with anti-viral drugs, also are used for severe infection, such as in the eyes, and to reduce severe pain. Nerve blocks can also help to control pain.
Post-herpetic neuralgia can be treated with an oral medication at night and frequent use of pain relievers during the day. The oral medications are called anti-depressants and anti-seizure medicines but are also used to treat other painful conditions. An ointment containing capsaicin, an extract of pepper, is helpful for some people. The ointment is applied to painful areas of the skin three to four times a day and the pain gradually eases over one to three weeks.