Shingles

What is shingles and how common is it?

Shingles is an infection of a nerve caused by the varicella-zoster virus. It is the same virus that causes chickenpox. Anyone who has had chickenpox in the past may develop shingles.

About 1 in 5 people have shingles at some time in their life. It can occur at any age, but it is most common in people over the age of 50. It is uncommon to have shingles more than once, but about 1 in 50 people have it two or more times in their life.

How does shingles occur?

Most people have chickenpox at some stage (usually as a child). The virus does not completely go after you have chickenpox. Some viruses remain dormant (inactive) in the nerve roots next to your spinal cord. They do no harm there, and cause no symptoms. For reasons that are not clear, the virus may begin to multiply again (reactivate). This is often many years later. The 'activated' virus travels along the nerve to the skin and causes shingles.

In most cases, an episode of shingles occurs for no apparent reason. Sometimes a period of stress or illness seems to trigger it.

What are the symptoms of shingles?

The virus usually affects one nerve only, on one side of the body. Symptoms occur in the area of skin that the nerve supplies. Occasionally, two or three nerves next to each other are affected. The most commonly involved nerves are those supplying the skin on the chest or abdomen. The upper face (including an eye) is also a common site for shingles. The usual symptoms are pain and a rash.

• The pain is a localised 'band' of pain. It can be anywhere on your body, depending on which nerve is affected. The pain can range from mild to severe. You may have a constant dull, burning, or gnawing pain. In addition, or instead of this, you may have sharp and stabbing pains that come and go. The affected area of skin is usually tender.
• A rash appears 2-3 days after the pain begins. Red blotches appear that quickly develop into itchy blisters. The rash looks like chickenpox, but only appears on the band of skin supplied by the affected nerve. New blisters may appear for up to a week. They dry up, form scabs, and gradually fade away. Slight scarring may occur where the blisters had been.

An episode of shingles usually lasts 2-3 weeks. In some cases there is just a rash but no pain. Rarely, there is no rash but just a band of pain. Some people also feel feverish and unwell for a few days.
Is shingles infectious?

Yes. You can catch chickenpox from someone with shingles if you have not had chickenpox before. Most adults and older children have already had chickenpox, and so are immune. However, if you are pregnant and have not had chickenpox, you should avoid people with shingles. Also, if you have a poor immune system, you should avoid people with shingles. For example, if you take chemotherapy or high dose steroids, if you have leukaemia, or if you are HIV positive. The shingles rash is infectious until all the blisters have scabbed and are dry.

You cannot catch shingles itself from someone who has shingles.

Are there any complications from shingles?

Most people do not have any complications. Those that sometimes occur include the following.

• Postherpetic neuralgia is the most common complication. This means the nerve pain (neuralgia) of shingles persists after the rash has gone. This is uncommon in people aged under 50. In those aged over 60, up to 1 in 4 people who have shingles have pain that lasts more than a month. It usually eases gradually but in some people it may last months, or even longer in a few cases. The chance of pain persisting is reduced with treatment (see below).
• Sometimes the rash becomes infected with bacteria (bugs). The surrounding skin then becomes red and tender. Antibiotics may then be advised.
• Shingles of the eye may cause further eye problems.
• Very rarely, the nerve affected is a 'motor' nerve and not a usual sensory nerve (ones for touch). This may result in a weakness (palsy) of the muscle to which the nerve is attached.

What are the treatments for shingles?

No treatment may be needed
In many cases the rash and pain are mild, particularly if you are under 50. The pain tends to be more severe, and treatment more likely to be needed, if you are over 60.

General measures
Loose fitting cotton clothes are best to reduce irritating the affected area of skin. Pain may be eased by cooling the affected area with ice cubes (wrapped in a plastic bag), wet dressings, or a cool bath. Soothing creams or lotions, such as calamine, may help.

Painkillers
Paracetamol, or paracetamol combined with codeine, usually gives some relief. Painkillers are best taken regularly to keep 'on top of the pain' rather than now and then. Stronger painkillers are sometimes needed.

Antiviral medicines
There are several types of antiviral medicine which include aciclovir, famciclovir, and valaciclovir. One may be advised:

• if you are aged over 60.
• if shingles affects your eye (at any age).
• if you have a poor immune system (at any age).

An antiviral medicine does not kill the virus but works by stopping the virus from multiplying. It reduces the risk of pain persisting into postherpetic neuralgia (described above) by about a half. An antiviral medicine is not usually needed for most healthy people under the age of 60 as symptoms are usually not too bad, and tend to settle quickly. If an antiviral medicine is advised, it has to be started within 72 hours of the rash appearing to be of any benefit. A seven day course is usual for adults.

Antidepressant medicines
You may be advised to take an antidepressant medicine in the 'trycyclic' group if:

• the pain is severe or not settling
• you develop postherpetic neuralgia

An antidepressant is not used here to treat depression. Tricyclic antidepressants ease neuralgia (nerve pain) separate to their action on depression. There are several tricyclic antidepressants, but amitriptyline is the one commonly used for nerve pain. If an antidepressant is advised, you should take it regularly. It may take up to two or more weeks for it to become fully effective.

Some experts say that all people over the age of 60 with shingles should take a tricyclic antidepressant. This is because there is some evidence to suggest that taking an antidepressant reduces your chance of developing postherpetic neuralgia (which occurs more commonly in people aged over 60).

© EMIS and PIP 2004   Updated: March 2002   CHIQ Accredited   PRODIGY Validated