Shingles (Herpes Zoster)

What is shingles and how common is it?

Shingles is an infection of a nerve and the area of skin supplied by the nerve. It is caused by a virus called the varicella-zoster virus. It is the same virus that causes chickenpox. Anyone who has had chickenpox in the past may develop shingles. Shingles is sometimes called herpes zoster. (Note: this is very different to genital herpes which is caused by a different virus called herpes simplex.)

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 shingles 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 virus particles remain 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 years later. The 're-activated' virus travels along the nerve to the skin to cause shingles.

In most cases, an episode of shingles occurs for no apparent reason. Sometimes a period of stress or illness seems to trigger it. A minor 'ageing' of the immune system may account for it being more common in older people. (The immune system keeps the virus inactive and prevents it from multiplying. A slight weakening of the immune system in older people may account for the virus 'reactivating' and multiplying to cause shingles.)

Shingles is also more common in people with a poor immune system. For example, shingles commonly occurs in younger people who have HIV/AIDS or whose immune system is suppressed with treatment such as steroids or chemotherapy.

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. The usual symptoms are pain and a rash. 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.

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, you may have sharp and stabbing pains that come and go. The affected area of skin is usually tender.

The rash typically 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. The soft tissues under and around the rash may become swollen for a while due to inflammation caused by the virus. The blisters then dry up, form scabs, and gradually fade away. Slight scarring may occur where the blisters had been. The picture shows a scabbing rash (a few days old) of a fairly bad bout of shingles. In this person it has affected a nerve, and the skin that the nerve supplies, on the left side of the abdomen.

An episode of shingles usually lasts 2-4 weeks. In some cases there is a rash but no pain. Rarely, there is no rash but just a band of pain.

You may also feel feverish and unwell for a few days.

Is shingles contagious?

Yes, you can catch chickenpox from someone with shingles if you have not had chickenpox before. (You cannot get shingles itself from someone who has shingles.) The shingles rash is contagious until all the blisters have scabbed and are dry. But note: most adults and older children have already had chickenpox, and so are immune. Also, if the blisters (vesicles) are covered with a dressing, it is unlikely that the virus will pass on to others. This is because the virus is passed on by direct contact with the blisters. (Therefore, if you have a job you can return to work once the blisters have dried up, or earlier if you keep the rash covered and feel well enough.)

However, as a general rule, pregnant women who have not had chickenpox should avoid people with shingles. (See separate leaflet called 'Chickenpox, Shingles and Pregnancy'.) Also, if you have a poor immune system, you should avoid people with shingles. (See below for a list of people who have a poor immune system.) These general rules are to 'play safe', as it is direct contact with the rash that usually passes on the virus.

Also, to play safe and not risk passing on the virus to others who may not have had chickenpox, you should not share towels, go swimming, or play contact sports such as rugby whilst you have a shingles rash.

Are there any complications from shingles?

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

Postherpetic neuralgia

This is the most common complication. It is where the nerve pain (neuralgia) of shingles persists after the rash has gone. This problem is uncommon in people aged under 50. However, up to 1 in 4 people over the age of 60 who have shingles have pain that lasts more than a month. The older you are, the more likely it will occur. The pain usually eases gradually. However, in some people it lasts months, or even longer in a few cases. The chance of pain persisting is reduced with treatment.

See a separate leaflet called 'Postherpetic Neuralgia' for details.

Skin infection

Sometimes the rash becomes infected with bacteria (germs). The surrounding skin then becomes red and tender. If this occurs you may need a course of antibiotics.

Eye problems

Shingles of the eye can cause inflammation of the front of the eye. In severe cases it can lead to inflammation of the whole of the eye which may cause loss of vision.

Weakness

Sometimes, 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 muscles that are supplied by the nerve.

Various other rare complications

For example, infection of the brain by the varicella-zoster virus, or spread of the virus throughout the body. These are very serious, but rare. People with a poor immune system who develop shingles have a higher than normal risk of developing rare or serious complications. (For example, people with HIV/AIDS, people on chemotherapy, etc, - see below.)

What are the treatments for shingles?

Two main aims of treating shingles are:

1. To ease any pain and discomfort during the episode of shingles.
2. To prevent, as much as possible, postherpetic neuralgia from developing.

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. A non-adherent dressing that covers the rash when it is blistered and raw may help to reduce pain caused by contact with clothing. Oily calamine lotion may be helpful if the rash is itchy.

Painkillers

For example, paracetamol, or paracetamol combined with codeine, or anti-inflammatory drugs such as ibuprofen may give some relief. Strong painkillers such as oxycodone and tramadol may be needed in some cases.

Antiviral drugs

Antiviral drugs include aciclovir, famciclovir, and valaciclovir. An antiviral drug does not kill the virus but works by stopping the virus from multiplying. So, it may limit the severity of symptoms of the shingles episode. It had also been hoped that antiviral drugs would reduce the risk of pain persisting into postherpetic neuralgia. However, the research so far has shown that the current antiviral drugs taken during an episode of shingles do not seem to have much impact on the prevention of postherpetic neuralgia. Further research is needed in this area to determine if certain groups of patients do benefit and if newer antiviral drugs can prevent postherpetic neuralgia.

An antiviral drug is most useful when started in the early stages of shingles (within 72 hours of the rash appearing). However, in some cases your doctor may still advise an antiviral drug even if the rash is more than 72 hours old - particularly in elderly people with severe shingles, or if shingles affects an eye.

Antiviral drugs are not advised 'routinely' for everybody with shingles. For example, young adults and children who develop shingles on their abdomen very often have mild symptoms and have a low risk of developing postherpetic neuralgia. Therefore, in this situation an antiviral drug is not necessary. Your doctor will advise if you should take an antiviral drug.

As a general rule, the following groups of people who develop shingles will normally be advised to take an antiviral drug:

• If you are over the age of 50. The older you are, the more risk there is of severe shingles or complications developing, and the more likely you are to benefit from treatment.
• If you are of any age and have any of the following:
  • Shingles that affects the eye or ear.
  • A poorly functioning immune system (see later who this includes).
  • Shingles that affects any parts of the body apart from the trunk (that is, shingles affecting an arm, leg, neck, or genital area).
  • Moderate or severe pain.
  • Moderate or severe rash.

If prescribed, a course of an antiviral drug normally lasts seven days.

Antidepressant and anticonvulsant drugs

If the pain during an episode of shingles is severe, or if you develop postherpetic neuralgia, you may be advised to take:

• An antidepressant drug in the 'tricyclic' group. An antidepressant is not used here to treat depression. Tricyclic antidepressants such as amitriptyline, imipramine, and nortriptyline ease neuralgia (nerve pain) separate to their action on depression. OR:
• An anticonvulsant drug such as gabapentin. They also ease neuralgic pain separate to their action to control convulsions.

If an antidepressant or anticonvulsant is advised, you should take it regularly as prescribed. It may take up to two or more weeks for it to become fully effective to ease pain. In addition to easing pain during an episode of shingles, they may also help to prevent postherpetic neuralgia.

Steroid medication

Steroids help to reduce inflammation. A short course of steroid tablets (prednisolone) may be considered in addition to antiviral medication. This may help to reduce pain and speed healing of the rash. However, the use of steroids in shingles is controversial. Your doctor will advise. Steroids do not prevent postherpetic neuralgia.

People with shingles and a poor immune system

If you have a poor immune system (immunosuppression) and develop shingles, then see your doctor straight away. You will normally be given antiviral medication whatever your age, and will be monitored for complications. People with a poor immune system include:

• People taking high dose steroids. (This means adults taking 40 mg prednisolone (steroid tablets) per day for more than one week in the previous three months. Or, children who have taken steroids within the past three months, equivalent to prednisolone 2 mg/kg per day for at least one week, or 1 mg/kg per day for one month.)
• People on lower doses of steroids in combination with other immunosuppressant drugs.
• People taking anti-arthritis drugs that can affect the bone marrow (for example, adalimumab, anakinra, azathioprine, ciclosporin, cyclophosphamide, etanercept, gold, infliximab, leflunomide, methotrexate, penicillamine, sulfasalazine).
• People being treated with chemotherapy or generalised radiotherapy, or who have had these treatments within the past six months.
• People who have had an organ transplant and are on immunosuppressive treatment.
• People who have had a bone marrow transplant and who are still immunosuppressed.
• People with impaired cell immunity (for example, severe combined immune deficiency syndromes, DiGeorge syndrome).
• People who are immunosuppressed with HIV infection.

Can shingles be prevented?

Shingles can only be prevented if you never have chickenpox, or if you have very good immunity against the chickenpox virus (that is, against the varicella-zoster virus). Most people in the UK have chickenpox as a child. However, there is a vaccine against the varicella-zoster virus which has been used routinely in children in the USA since 1996. It is not given routinely in the UK. The vaccine has reduced the incidence of chickenpox in the USA. Time will tell if this has a knock on effect of reducing the incidence of shingles when these children are older.

Also, a trial of the vaccine given to people aged 60 was reported in 2005. The theory was that although these people will have had chickenpox when younger, the vaccine given at this age would boost the waning immunity against the virus. This may help to reduce the risk of developing shingles in older age. The result of the trial was very encouraging. It found that the number of cases of shingles and postherpetic neuralgia was reduced in those who were vaccinated compared to those not vaccinated. Further research is needed to determine the place of this vaccine in older people.

References

• Shingles, Clinical Knowledge Summaries (2008)
• Wareham DW, Breuer J; Herpes zoster. BMJ. 2007 Jun 9;334(7605):1211-5.
• Lancaster T, Silagy C, Gray S; Primary care management of acute herpes zoster: systematic review of evidence from randomized controlled trials. Br J Gen Pract. 1995 Jan;45(390):39-45. [abstract]
• Oxman MN, Levin MJ, Johnson GR, et al; A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults.; N Engl J Med. 2005 Jun 2;352(22):2271-84. [abstract]
• Li Q, Chen N, Yang J, et al; Antiviral treatment for preventing postherpetic neuralgia. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD006866. [abstract]