Shingles

What Is Shingles? What Causes Shingles?

Shingles is caused by the herpes varicella-zoster (or simply zoster) virus. This virus also causes chickenpox. Most of us get chickenpox during childhood, but after we recover the virus remains inactive (dormant) in our nervous system. Our immune system stops the virus from becoming active. However, later in life it may become reactivated, causing shingles. Shingles is an infection of a nerve and the area of skin around it.

According to Medilexicon's medical dictionary,:

herpes zoster (shingles) is "an infection caused by a herpes virus (varicella-zoster virus), characterized by an eruption of groups of vesicles on one side of the body following the course of a nerve due to inflammation of ganglia and dorsal nerve roots resulting from activation of the virus, which in many instances has remained latent for years following a primary chickenpox infection; the condition is self-limited but may be accompanied by or followed by severe postherpetic pain."

A study found that most Americans are in the dark regarding shingles.

What are the symptoms of shingles?

A bout of shingles will normally last from 2 to 4 weeks. The patient will generally feel a tingling sensation in the affected area at first. This will be followed by pain, and then a rash.

Although the chest and abdomen are the most likely parts of the body to experience pain and a rash, shingles can affect any part, including arms, legs, and even the face and eyes.
  • Pain - the pain in the affected area tends to be continuous. Some describe it as a dull pain, while others experience a burning sensation. There may also be occasional stabbing pains. The affected area will nearly always be tender.
  • Rash - about two to three days after the onset of pain the rash will appear. It usually emerges on just one side of the body, and develops at the area of the affected nerve. It starts off as red blotches on the skin, and rapidly develops into itchy blisters; similar to those of chicken pox. Each blister may be there for about one week, then they become yellowish and dry out. Some patients may experience slight scarring of the skin.
  • Postherpetic neuralgia - some patients experience severe nerve pain (neuralgia). If the nerves are damaged (postherpetic neuralgia) the pain can last for a very long time, even months or years after symptoms have disappeared.
Sometimes there may be additional symptoms, although they are nearly always mild. They might include:

Risk factors for shingles

Any person who has had chickenpox can potentially develop shingles. However, it is much more common among people over the age of 60 (over 50% of cases). The risk of shingles is also much higher among people with weakened immune systems, such as those with HIV/AIDS, patients receiving steroids, radiation and chemotherapy, or those with a history of bone or lymphatic cancer.
Most people who develop shingles only do so once. However, recurrences can happen.

Anyone who has never had chicken pox can become infected by somebody with shingles. This generally happens through direct contact with open sores of the shingles rash. However, that person will develop chickenpox, not shingles. Even so, a chicken pox infection can be dangerous for some people with deficient immune systems. A person with a normal immune system who has already had chicken pox cannot become infected by a person with shingles.

Researchers from Texas, USA, found that those with a family history of shingles may be more susceptible to developing the disease. A person with shingles and blisters should avoid contact with people who have never had chickenpox, people with weakened immune systems, infants and newborn babies, and pregnant women.

German scientists found that some arthritis drugs may be linked to an increased risk of developing shingles.

How is shingles diagnosed?

Most GPs (general practitioners, primary care physicians) can diagnose shingles by the symptoms and a rash. Testing is not generally needed. Sometimes doctors may take a tissue scraping or culture of the blisters for testing in the laboratory.

If a GP suspects there is a risk for the patient of a complication he/she may be referred to a specialist. If shingles is affecting the patient's eyes he/she may be referred to an eye specialist (ophthalmologist) - there is a risk that an eye problem may result in permanent vision deficiency. Patients on chemotherapy/radiotherpy, those with HIV/AIDS, as well as anybody with a weakened immune system may also be referred to a specialist. People with weakened immune systems run a higher risk of complications caused by shingles.

A GP may also refer a patient to a specialist if the patient is not responding to treatment.

What is the treatment for shingles?

Although there is no cure for shingles, there is a lot that can be done to relieve symptoms:
  • Shingles rash - keep the rash as dry and as clean as possible. This helps reduce the risk of bacterial infection. Patients find loose-fitting clothes easier to wear than tight-fitting ones.
  • Pain - typically, over-the-counter painkillers such as ibuprofen paracetamol (acetaminophen, Tylenol) are effective painkillers for people with shingles. If the pain is very severe the patient may require a prescription-only medication. Ibuprofen is unsuitable for patients with stomach problems, asthma, severe liver disease, or kidney problems. Pregnant women should not generally take ibuprofen. The painkiller oxycodone is effective at treating the acute pain of shingles, according to a study. Another study found that a single epidural injection of steroids and local anaesthetics is not effective for the prevention of long-term pain in shingles.
  • Antidepressants - some patients who experience severe pain may be prescribed an antidepressant. Antidepressants are sometimes effective for pain management, especially if the pain is severe or long-lasting. In the UK the most commonly prescribed antidepressants for patients with shingles are amitriptyline, imipramine and nortriptyline. These medications may have the following side-effects: constipation, blurred vision, weight gain, drowsiness, problems urinating, and dry mouth. The antidepressant dosage for shingles is usually much lower than for clinical depression. Some antidepressant may take a while before the benefits are felt.
  • Anticonvulsants - these medications are usually prescribed to control seizures. However, they can be effective in helping the patient control nerve pain. The most commonly prescribed anticonvulsant medication for shingles patients in the UK is Gabapentin. Side effects may include swollen ankles, dizziness and drowsiness. It may take a while before the patient starts noticing the benefits.
  • Antivirals - these drugs do not kill the shingles virus, but they can stop if from reproducing. They are often effective in reducing the severity of symptoms, especially if taken within 72 hours of the appearance of the skin rash. Commonly prescribed antivirals include aciclovir, valaciclovir and famciclovir. A course of antivirals lasts about one week. Generally patients are prescribed antivirals if they are aged over 50, have symptoms which are affecting their eyes, have weakened immune systems, have moderate to severe pain, have a moderate to severe rash, and have a rash outside the torso, such as the arms, legs or neck. A GP will discuss the pros and cons of antiviral medications for a pregnant patient with a specialist and the patient herself. A possible new anti-viral drug designated FV-100, which is still in clinical trials (June 2009) may help patients with shingles, a study reported.

What are the complications of shingles?

Complications are much more likely if the patient has a weakened immune system. Possible complications may include:
  • Infection - the rash may become infected. Usually, a course of antibiotics is all that is needed.
  • Loss of pigmentation - the patient may have white patches after the rash has gone.
  • Scarring - sometimes the blisters can leave scars. However, this is extremely uncommon.
  • Ramsay-Hunt syndrome - the facial nerve becomes infected. The onset of Ramsay Hunt syndrome can be frightening. Some people may wonder whether they are having a stroke. It is important that it is treated promptly because in rare cases it can lead to permanent facial muscle weakness and hearing loss. Symptoms of Ramsay Hunt syndrome include earache, deafness, dizziness and paralysis of the face. The pain usually improves within 48 hours.
  • Eye ulceration and permanent scarring - the cornea (surface of the eye) may become scarred and the iris and ciliary body (ring of muscle behind the iris) may become inflamed.
  • Encephalitis - inflammation of the brain - the patient has a very high fever, confusion, headaches, lethargy and limb weakness. This is very rare.
  • Postherpetic neuralgia - this may be the result of nerve fiber damage. Damaged fibers can't send messages from the skin to the brain. Messages become confused, causing pain - neuralgia - which may become persistent long after other shingles signs have gone.

Prevention

A National Institutes of Health (NIH) funded study (USA) found that Tai Chi helps boost immunity to the shingles virus in older adults.

There are two vaccines which can help prevent shingles - the varicella (chickenpox) vaccine and the varicella-zoster (shingles) vaccine.
  • Chickenpox vaccine - This vaccine (Viravax) is routinely given to children aged 12 to 18 months to prevent chickenpox. Experts recommend it also for adults and older children who have never had chickenpox. The vaccine does not provide 100% immunity, but it does considerably reduce the risk of complications and severity of the disease.
  • Shingles vaccine - this vaccine (Zostavax) can help protect adults over 60 who have had chickenpox. It does not provide 100% immunity but does considerably reduce the risk of complications and severity of shingles. Experts recommend that people over 60 have this vaccine, regardless of whether or not they have had shingles before. The vaccine is preventative, and is not used to treat people who are infected. The following people should not have the shingles vaccine:

    • Those who have had a life-threatening reaction to gelatin, neomycin (an antibiotic), or any other shingles vaccine component.
    • People who have a weakened immune system
    • Patients receiving steroids, radiotherapy, and/or chemotherapy
    • Patients with a history of bone marrow or lymphatic cancer
    • Patients with active, untreated TB (tuberculosis)

    Doctors say people with a mild cold may take the vaccine, but not those who are moderately or severely ill (they should wait till they are recovered).

 

No comments:

Post a Comment

Share |