The zoster manifests as rash pain along with a nerve or nerve ganglia. These rashes occur as a result of the reactivation of the virus that causes chickenpox, varicella-zoster virus (VZV). Shingles most often affect the chest or face, but all parts of the body can be affected.
Sometimes the pain caused by shingles persists for months or even years after the rash is healed: this pain is called neuralgia or post-zosterian pain.
Cause of Shingles
As a result of chickenpox, almost all viruses are destroyed except for a few. They remain dormant in the nervous ganglia for several years. With age or because of a disease, the immune system can lose its ability to control the virus, which can reactivate. An inflammatory reaction then develops in the ganglia and in the nerves, causing the appearance of vesicles arranged in clusters on the skin.
It may be that the adults already infected who have been in contact with chickenpox affected children receive protection increased against shingles. Scientists believe that a second exposure to the virus stimulates the immune system and thus helps keep the virus dormant.
Who is affected?
About 90% of adults in the world have already had chickenpox. They are therefore carriers of the varicella-zoster virus. About 20% of them will develop shingles in their lifetime.
Evolution of Shingles
In the absence of treatment, the shingles lesions last on average 3 weeks. Most of the time, a single shingles crisis occurs. However, it happens that the virus reactivates several times. That’s what happens in the case of about 1% of sufferers.
The pain persists sometimes after the healing of the cutaneous lesions: it is the post-zoster neuralgia (or post-zoster neuralgia). This pain is compared to that of sciatica. People who suffer from it say that they feel real “electric shocks”. The heat, the cold, the simple rubbing of a garment on the skin or the breath of the wind can become unbearable. The pain can last for weeks or months. Sometimes she never stops.
As much as possible, this situation is avoided, which can become a considerable source of physical and psychological suffering: the neuralgic pains can be persistent, intense and difficult to treat effectively. Taking antiviral medications as soon as shingles appear will help prevent them (see Medical Treatments section).
The risk of post-zona neuralgia increases with age. For example, according to a study conducted in Iceland with 421 people, 9% of people aged 60 and over felt pain 3 months after a first shingles crisis, compared with 18% of people aged 70 and over.
Post-zona neuralgia is thought to be caused by the damage of nerve fibers, which begin to send confused messages of pain to the brain.
Other types of complications can occur, but they are rare: eye problems (which can go as far as blindness), facial paralysis, non-bacterial meningitis or encephalitis.
The Shingles is not spread from one person to another. However, the fluid inside the red vesicles that form during a shingles crisis contains several particles of the chickenpox virus. This liquid is very contagious: a person who touches it can get chickenpox if she has never had it. To enter the body, the virus must come into contact with a mucous membrane. It can infect someone who rubs their eyes, mouth or nose, for example, with a contaminated hand.
The hand washing helps prevent transmission of the virus. It is also advisable to avoid physical contact when the liquid flows from the vesicles. People who have not had chickenpox and whose infection could have serious consequences should be extra careful: this is the case, for example, with pregnant women (the infection can be dangerous for the fetus), people with weakened immune systems and newborns.
Symptoms of shingles
- The person with shingles experiences a burning sensation, tingling or increased sensitivity on an area of the skin along with a nerve, usually on one side of the body. If it occurs on the thorax, shingles can create a more or less horizontal pattern that evokes the shape of a hemi-belt (in Latin, zona means belt).
- From 1 to 3 days later, diffuse redness appears on this area of the skin.
- Then, several red vesicles filled with liquid and resembling the pimples of chickenpox erupts. They cause itching, dry out in 7 to 10 days, and disappear after 2 to 3 weeks, sometimes a little more.
- Between 60% and 90% of people with shingles experience the acute local pain of varying duration and intensity. It may look like a burn or electric shock, or sharp twitching. Sometimes it is so strong that it can be mistaken for a heart attack, appendicitis or sciatica.
- Some people have fever and headaches.
People at risk for Shingles
- Shingles are more common in people over 60 years of age because immunity weakens with age and the virus can multiply more easily.
- Various treatments and health problems increase the risk of shingles by weakening immunity (cancer, diabetes, corticosteroids, immunosuppressants, etc.). However, this type of risk factor is found in only 4% of those affected.
No risk factor is officially recognized.
- Researchers question whether there is a possible link between shingles and chronic stress. The studies carried out so far lead to conflicting results: some suggest a link, and others, not.
- A study in North Carolina suggests that exposure to chemicals increases the risk of developing shingles. The study included, among others, 900 participants aged 18 to 40 and living 2.5 miles from a pesticide or other chemical landfill (unused products that companies must have). These participants had shingles attacks 2 times more than the 742 respondents residing at a greater distance from the site, the surrounding communities. According to the authors of the study, exposure to certain chemicals would weaken immune defenses.
Prevention of shingles
|Measures to prevent shingles|
|The best way to prevent it would be to not get chickenpox. This is not easy because it spreads easily in young children. Varicella vaccination may provide some protection against shingles. However, it will take several years to test this hypothesis, since this vaccine has only been available since 1998 in Canada and 2004 in France. Note that the varicella vaccine is also for adults who have never had chickenpox.
Strengthen your immune system. To prevent the virus from becoming active, it is best to strengthen the immune system through a healthy diet, regular physical activity and periods of rest. A small, controlled study of 36 people over the age of 60 indicates that regular tai chi improves immune defenses against the chicken pox virus. Thus, tai chi would help prevent the reactivation of chickenpox virus in the form of shingles. Another study of 112 healthy adults aged 59 to 86 suggests that tai chi strengthens immune defenses against varicella virus after vaccination against varicella (Varivax). See our fact sheet Strengthen your immune system.
A vaccine against shingles now available in Canada and France for the indication “Prevention of shingles and post-herpetic pain in persons over 65 years of age on a one-shot schedule”. Zostavax is a new vaccine that helps prevent shingles. It is intended for people aged 60 and over (65 years old in France) who have already had chickenpox. It is obtained by prescription and has certain contraindications. This vaccine is different from that intended to protect against chicken pox. It does not protect shingles but halves the risk of getting it, on average. In addition, it decreases the severity of symptoms of shingles, as well as the risk of neuralgia post-zona (two-thirds). These data come from a study conducted by the manufacturer of 38,500 men and women aged 60 and over. The vaccine is more effective in people 60 to 69 years old than 70 years and older.
In August 2008, Health Canada approved Zostavax. Since September 2009, Canadians who wish can be vaccinated (a single dose is required at a cost of $ 150). This vaccine has been on the market since 2006 in the United States, some European Union countries and Australia. In France, it is reimbursed at 30% by Social Security in respect of its indication.
|Measures to prevent post-zona neuralgia|
|It is important to consult a doctor as soon as symptoms of shingles appear. He will prescribe antiviral treatments. When these are taken early, they probably help to limit the occurrence of post-shingal neuralgia. If neuralgia occurs, antivirals taken early may reduce its duration.
To avoid complications in the eyes, it is also important to see an ophthalmologist as soon as shingles touch the upper part of the face.
Medical treatments for shingles
|Important. Consult a doctor as soon as the first symptoms of shingles appear. The earlier the treatment, the better it’s effectiveness. Ideally, an antiviral drug should be taken within 3 days of the appearance of a lesion.|
The antiviral (drugs that fight viruses), and France acyclovir (Zovirax) and valaciclovir (Zelitrex), which are the two antiviral with Marketing Authorization in the market, but also in Canada famciclovir ( Famvir) and valacyclovir (Valtrex) may be prescribed. They are taken orally. They are well tolerated and have few side effects. Antivirals accelerate healing, reduce acute pain, and probably limit the onset of post-zoster neuralgia if taken within the first 3 days of rash.
Of analgesics can help relieve pain mild or moderate, in addition to antiviral drugs, such as paracetamol (also called acetaminophen) (Tylenol, Panadol, Paracétamol Canada, Doliprane, Daffalgan, Efferalgan in France etc. ). Narcotic analgesics, also known as opiates, may be prescribed as needed: for example, tramadol or codeine, or even morphine (in small doses).
Note. The nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil France, Canada Motrin, etc.) are not shown in the shingles.
Of steroids (such as cortisone) may also be prescribed, but less frequently. In combination with antivirals, they can help reduce (modestly) the duration and intensity of symptoms of shingles. However, they do not help prevent post-shingal neuralgia. These medications are usually reserved for people with very uncomfortable symptoms, given their side effects.
The post-herpetic neuralgia may require, in addition to the use of conventional analgesics, treatments using tricyclic antidepressants, antiepileptics or narcotic analgesics, depending on the intensity of pain. In France, there is also anesthetic plaster (Versatis 5%) to be applied to the pain area once a day for a maximum of 12 hours per 24 hours.