When the itchy red spots of childhood chickenpox disappear and life returns to normal, the battle with the virus that causes chickenpox seems to be won. But for all too many of us this triumph of the body's immune system over the virus that causes chickenpox is only temporary. The virus has not been destroyed, but lays low, ready to strike again later in life. This second eruption of the chickenpox virus is the disease called shingles.

Anyone who's ever had chickenpox is at risk for shingles. The chickenpox virus -- varicella zoster virus -- never really goes away. It's a herpes virus, after all. It lies dormant in the nerves. When a person's immunity dips, the virus wakes and causes the painful sores called shingles.

You cannot develop shingles unless you have had an earlier bout of chickenpox, and everyone who has had chickenpox is at risk for shingles. The typical symptoms of this common neurological disorder: more pain compared to chickenpox but less itching. While young people do develop shingles, the disease most often strikes in later years.

Scientists call the chickenpox/shingles-causing agent varicella-zoster. Varicella is a Latin word meaning "little pox" to distinguish the virus from smallpox, the highly contagious and often fatal scourge that disfigured or killed millions of people, especially during the Middle Ages. Zoster is the Greek word for "girdle"; shingles often produces a girdle of blisters or lesions around the waist. This striking pattern also gives the disease its common name: the word shingles comes from cingulum, the Latin word for belt or girdle.

About 10 percent of normal adults can be expected to get shingles during their lifetimes, usually after age 50. The incidence increases with age so that shingles is 10 times more likely to occur in adults over 60 than in children under 10. Most people who get shingles develop immunity to the virus and will not get the disease again. However, shingles may recur in some individuals. These cases usually involve people with declining or compromised immune systems, such as those infected with HIV or receiving chemotherapy.

A person who is suffering from a disease that damages the immune system, or who is taking anticancer drugs that suppress the immune system, is a prime candidate for an attack of shingles. Even among healthy individuals, temporary depression of the immune system because of stress, a cold, and even sunburn may be associated with an attack of shingles.

Youngsters whose mothers had chickenpox late in pregnancy ( 5 to 21 days before giving birth ) are also vulnerable to shingles. Sometimes these children are born with chickenpox or develop a typical case within a few days.

Scientists believe that in the original battle with the chickenpox virus some of the virus particles leave the skin blisters and move into the nervous system. There the viruses settle down in an inactive (latent) form inside specific nerve cells (neurons) that relay information to the brain about what your body is sensing ( whether your skin feels hot or cold, whether you've been touched or feel pain). These lie in clusters (ganglia) adjacent to the spinal cord and brain and are one type of sensory neurons.

When the chickenpox virus reactivates, the virus moves down the long nerve fibers that extend from the sensory cell bodies to the skin. The viruses multiply, the telltale rash erupts, and the person now has herpes zoster, or shingles. With shingles, the nervous system is more deeply involved than it was during the bout with chickenpox, and the symptoms are often more complex and severe.

The virus responsible for shingles and chickenpox belongs to a group of viruses called herpesviruses. This group includes the herpes simplex virus that causes cold sores, fever blisters, mononucleosis, genital herpes ( a sexually transmitted disease), and Epstein-Barr virus involved in infectious mononucleosis. Like the shingles-causing virus, many other herpesviruses can take refuge in the nervous system after an individual has suffered an initial infection. These viruses may remain latent for years, then travel down nerve cell fibers to cause a renewed infection.

The varicella-zoster virus looks as though it were designed by a mathematician. It is a microscopic sphere encasing a 20-sided geometric figure called an icosahedron. Inside the icosahedron is the genetic material of the virus, deoxyribonucleic acid (DNA). When activated, the virus reproduces inside the nucleus of an infected cell. It acquires its spherical wrapping as it buds through the nuclear membrane.

As early as 1909 a German scientist suspected that the viruses causing chickenpox and shingles were one and the same. In the 1920's and 1930's the case was strengthened. In an experiment, children were inoculated with fluid from the lesions of patients with shingles. Within 2 weeks about half the children came down with chickenpox. Finally in 1958 detailed analyses of the viruses taken from patients with either chickenpox or shingles confirmed that the viruses were identical.

This study also proved that a person with shingles can pass the virus to individuals who have never had chickenpox, but these individuals will develop chickenpox not shingles. A person with chickenpox cannot communicate shingles to someone else. In order for people to develop shingles they must already harbor the virus in their nervous system, and for those who do harbor the virus, having contact with someone with chickenpox will not trigger shingles. Additionally, a person with shingles cannot communicate shingles to another individual.

Many mothers-to-be are concerned about any infection contracted during pregnancy, and rightly so. It is well known that certain viruses can be transmitted across the mother's bloodstream to the fetus, or can be acquired by the baby during the birth process.

Maternal chickenpox poses some risk to the unborn child, depending upon the stage of pregnancy during which the mother contracts the disease. During the first 30 weeks, maternal chickenpox may, in some cases, lead to congenital malformations. Such cases are rare and experts differ in their opinions on how great the risk is.

If the mother gets chickenpox from 21 to 5 days before giving birth, the newborn may have chickenpox at birth or develop it within a few days, as noted earlier. But the time lapse between the start of the mother's illness and the birth of the baby generally allows the mother's immune system to react and produce antibodies to fight the virus. These antibodies can be transmitted to the unborn child and thus help fight the infection. Still, a third of the babies exposed to chickenpox in the 21 to 5 days before birth develop shingles in the first 5 years of life because the virus must also be fought by immune cells.

What if the mother contracts chickenpox at precisely the time of birth? In that case the mother's immune system has not had a chance to mobilize its forces. And although some of the mother's antibodies will be transmitted to the newborn via the placenta, the newborn will have precious little ability to fight off the attack because the immune system is immature. For these babies chickenpox can be fatal. They must be given "zoster immune globulin," a preparation made from the antibody-rich blood of adults who have recently recovered from chickenpox or shingles.

A new study offers insights into what helps -- and what does not help -- relieve long-lasting shingles pain.

Doctors call it postherpetic neuralgia or PHN. It's caused by nerve damage left behind by a case of shingles. Shingles itself comes from reactivation of a chickenpox virus, varicella zoster. The virus travels down nerve fibers to cause a painful skin rash. When the rash goes away, the pain usually goes with it. But for 12% to 15% of people the pain remains. If your shingles pain lasts eight to 12 weeks after the rash goes away, you're part of an unfortunate minority.

Among people with PHN, some have their pain resolve in the first year to 18 months after the shingles rash goes away. But if they have pain longer than that, it is not going to go away on its own. In either case, a person must deal with the pain.

A recent American Academy of Neurology review of postherpetic neuralgia treatments found many treatments that work quite well and are well tolerated. The best are the tricyclic antidepressants, followed by opioids. Some people benefit from the lidocaine patch or capsaicin. What should a patient try first? Treatment must be individualized, and a doctor's advice -- early on -- is crucial. The most important first step is to find out what drugs a patient is able to take. That decision is based on the patient's health, other current medications, and the side effects a patient has from certain drugs. If there are no contraindications, and the pain is debilitating, start a patient with tricyclic anti-depressants. If the pain is not that debilitating, try the lidocaine patch first. And if there is a contraindication to tricyclic anti-depressants, go with opioids. This decision has a lot to do with what patients can tolerate. If these individual medications don't work, try a combination of tricyclic anti-depressants and opioids. Such powerful combinations have powerful side effects, and patients and doctors must plan for them in advance.

Tai chi boosts shingles immunity in elderly people, new research shows. It adds to their general health, too -- especially when those in poor health practice the gentle meditation. Tai Chi fosters a calm and tranquil mind. It also affects the body.

Shingles is a debilitating illness. There are no medical treatments to prevent shingles. No medical treatment has yet been shown to boost shingles immunity. This novel behavioral intervention -- tai chi -- may have those beneficial effects. People who practice tai chi had improved ability to carry out day-to-day activities like climbing steps, walking, and carrying packages. Tai chi for the elderly is an idea whose time has come. It builds strength, endurance, mobility, balance, and cardiovascular health.