Overview

hingles, also known as herpes zoster, is a disease that affects an  estimated 2 in every 10 people in their lifetime. This year, more than 500,000 people will develop shingles.

Although it is most common in people over age 50, if you have had chickenpox, you are at risk for developing shingles. Shingles is also more common in people with weakened immune systems from HIV infection, chemotherapy or radiation treatment, transplant operations, and stress.

What is Shingles?

Shingles (herpes zoster) is an outbreak of rash or blisters on the skin that is caused by the same virus that causes chickenpox — the varicella-zoster virus. Shingles, or herpes zoster, is a common viral infection of the nerves, which results in a painful rash of small blisters on an area of skin anywhere on the body. Even after the rash is gone, the pain can continue for months, even years. The first sign of shingles is often burning or tingling pain, or sometimes numbness or itch, in one particular location on only one side of the body. After several days or a week, a rash of fluid-filled blisters, similar to chickenpox, appears in one area on one side of the body. Shingles pain can be mild or intense.  Some people have mostly itching; some feel pain from the gentlest touch or breeze.

The most common location for shingles is a band, called a dermatome, spanning one side of the trunk around the waistline.  Shingles is caused by the reactivation of the varicella-zoster virus, which causes chickenpox. After a person has had chickenpox, the virus lies dormant in certain nerves for many years. Herpes zoster is more common in persons with a depressed immune system, and in persons over the age of 50. According to the Centers for Disease Control and Prevention (CDC), shingles affects an estimated 600,000 to one million people each year. Clinical Features

The name 'shingles' is derived from the Latin word Cingulum, which means a girdle. This refers to the distribution of the rash (fluid-filled vesicles) in a girdle-like eruption round one half of the trunk. This distribution corresponds to the area of skin supplied by the branches of one or more of the main spinal nerves as they follow the course of corresponding ribs from the backbone forward to the breastbone. Less commonly, the rash appears on the face or neck.

The onset is often accompanied by a fever which may last from two to four days. At first there is pain in that area of skin supplied by the affected nerve, which means that the pain appears before the rash. The pain may be intense, in fact so painful that typically people can't bear clothes touching the affected area. This pain may last for a few weeks; and in frail and elderly persons it may persist for months or even years after the eruption has disappeared. This so-called 'postherpetic neuralgia' (PHN) occurs in half of all patients over 60 years of age.

In older persons, the disease may also affect the fifth nerve of the brain, giving rise to shingles on one side of the face and forehead. The condition is characterized by intense pain and is often followed by a particularly intractable form of neuralgia, and subsequent scarring is often severe.

In some cases there is ulceration of the front of the eyeball, which may be followed by scarring and marked impairment of vision. This is due to involvement of the trigeminal nerve which supplies the skin of the face.

It is also possible for shingles to appear in other areas such as the thigh and upper arm.

Many people are surprised at how ill they feel with shingles and, as with many other virus diseases, depression is often a feature.

Ramsay Hunt Syndrome II

First described by Ramsay Hunt in 1907, RHS II is a common complication of shingles and is caused by the spread of the varicella-zoster virus to facial nerves. The condition is characterized by intense ear pain, a rash around the ear, mouth, face, neck, and scalp, and paralysis of facial nerves (which may or may not be permanent). Other symptoms may include hearing loss (which also may or may not be permanent), vertigo and tinnitus. There may also be loss of taste due to dryness of the mouth and tongue, which may also be noticed in the eyes.

How is shingles diagnosed?

In addition to a complete physical examination and medical history, diagnostic tests for shingles may include the following:

What is the prognosis?

For most healthy people, the lesions heal, the pain subsides within 3 to 5 weeks, and the blisters leave no scars.  However, shingles is a serious threat in immunosuppressed individuals — for example, those with HIV infection or who are receiving cancer treatments that can weaken their immune systems.  People who receive organ transplants are also vulnerable to shingles because they are given drugs that suppress the immune system.

A person with a shingles rash can pass the virus to someone, usually a child, who has never had chickenpox, but the child will develop chickenpox, not shingles.  A person with chickenpox cannot communicate shingles to someone else.  Shingles comes from the virus hiding inside the person's body, not from an outside source.

Complications of shingles:

Active shingles symptoms usually do not last longer than three to five weeks. However, complications do occasionally occur. The two major complications that can occur as a result of a case of shingles include the following:

How do people get shingles? (Pathogenesis)

Shingles is a re-emergence of the chickenpox virus, which can occur many years after the original chickenpox infection.

The original infection with varicella (as a child) is believed to occur by contact as well as via the respiratory route, but little is known for certain about what happens to it during the incubation period.

The chickenpox rash itself results from multiplication of the virus in epithelial cells of the skin. During this primary attack, virions (individual virus particles) move to the ganglia (a kind of 'junction box' of nerves beside the spine along sensory nerves (probably spread in Schwann cells of the nerve sheath). It persists in the neurons (nerve cells) as naked viral DNA. When the virus is re-activated it is thought to descend the sensory nerve by the same means as it ascended, namely within the axon cylinder.

Who will get shingles?

Anybody who has ever had chickenpox can develop shingles, and most people do have chickenpox in childhood. Prior to the general introduction of chickenpox vaccine, 90-95% of the population in the United States would get chickenpox in childhood. (There is no reason to suppose that the rate would be dissimilar in the United Kingdom). The risk of any individual of developing shingles in his or her lifetime is 20%.

People who have not had chickenpox cannot get shingles (some people with shingles claim that they have never had chickenpox - but this probably means that their original bout of chickenpox was so mild that it was not noticed (sub-clinical) or that the patient has forgotten because it was so long ago).

Shingles is most likely to occur in older people and it affects 1% of the 50-60 year age annually, with the incidence rising rapidly after that. Around 60% of 85 year olds will have suffered an attack.

The condition is particularly prevalent in patients suffering from Hodgkins disease, lymphatic leukaemia or other malignancies, or following treatment with immunosuppresive drugs or irradiation of or injury to the spine.

The protracted course of the disease in elderly people is probably due to their weaker immune systems.

What causes the virus to reactivate?

Usually the cause is a reduction in your body's natural resistance to disease, which may be caused by stress, through being generally 'run down', or occasionally, when the body's defences have been affected by certain drugs or other immune deficiencies.

As shingles is caused by reactivation of the dormant virus, it is possible to have shingles more than once.

Is shingles infectious?

You cannot do much to avoid shingles. It is not caught by contact with anyone with either shingles or chickenpox; it is merely reactivation of the virus with which you were infected as a child. However, it is possible for a person with shingles to transmit chickenpox to someone who has not had it before. Therefore it is advisable for a sufferer to stay away from other people, especially pregnant women and newborn babies, until the blisters have dried (usually about seven days).