Shingles is an infection of a nerve area caused by the varicella-zoster virus. It causes pain and a rash along a band of skin supplied by the affected nerve. Symptoms usually go within 2-4 weeks. Pain sometimes persists after the rash has gone, more commonly in people over the age of 50. Other complications are uncommon. Antiviral medication may be prescribed to limit the severity of the condition.
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 person in 50 has 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 reactivated 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 (immunosuppression). 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.
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 tummy (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 swelling (inflammation) caused by the virus. The blisters then dry up, form scabs, and gradually fade away. Slight scarring may occur where the blisters have 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 you have a high temperature (feel feverish) and unwell for a few days.
Is shingles contagious?
You can catch chickenpox from someone with shingles if you have not had chickenpox before. But most adults and older children have already had chickenpox, and so are immune. You cannot get shingles from someone who has shingles.
The shingles rash is contagious until all the blisters (vesicles) have scabbed and are dry. Also, if the blisters 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 Contact and Pregnancy.) Also, if you have a poor immune system (immunosuppression), 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 (PHN)
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 with shingles, over the age of 60, 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 separate leaflet called Postherpetic Neuralgia for details.
Sometimes the rash becomes infected with germs (bacteria). The surrounding skin then becomes red and tender. If this occurs you may need a course of medicines called antibiotics.
Shingles of the eye can cause swelling (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.
Sometimes the nerve affected is a motor nerve (ones which control muscles) 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
Examples are 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 (immunosuppression) 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:
- To ease any pain and discomfort during the episode of shingles.
- To prevent, as much as possible, PHN from developing.
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. Simple creams (emollients) may be helpful if the rash is itchy.
Painkillers - for example, paracetamol, or paracetamol combined with codeine (eg, co-codamol), or anti-inflammatory painkillers such as ibuprofen - may give some relief. Strong painkillers such as oxycodone and tramadol may be needed in some cases.
Antiviral medicines include aciclovir, famciclovir, and valaciclovir. An antiviral medicine 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 medicines would reduce the risk of pain persisting into PHN. However, the research so far has shown that the current antiviral medicines taken during an episode of shingles do not seem to have much impact on the prevention of PHN. Further research is needed in this area to determine if certain groups of patients do benefit and if newer antiviral drugs can prevent PHN.
An antiviral medicine 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 medicine even if the rash is more than 72 hours old - particularly in elderly people with severe shingles, or if shingles affects an eye.
Antiviral medicines are not advised routinely for everybody with shingles. For example, young adults and children who develop shingles on their tummy (abdomen) very often have mild symptoms and have a low risk of developing PHN. Therefore, in this situation an antiviral medicine is not necessary. Your doctor will advise if you should take an antiviral medicine.
As a general rule, the following groups of people who develop shingles will normally be advised to take an antiviral medicine:
- 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 (immunosuppression - 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 medicine normally lasts seven days.
Antidepressant and anticonvulsant medicines
If the pain during an episode of shingles is severe, or if you develop PHN, you may be advised to take:
- An antidepressant medicine 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 medicine 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 PHN.
Steroids help to reduce swelling (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 you. Steroids do not prevent PHN.
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 previous 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 medications that can affect the bone marrow.
- People being treated with chemotherapy or generalised radiotherapy, or who have had these treatments within the previous 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 an impaired immune system.
- People who are immunosuppressed with HIV infection.
Can shingles be prevented?
There is a vaccine against the varicella-zoster virus which has been used routinely in the USA since 1996 to protect children against chickenpox. It is not given routinely in the UK, but is available for prescription on the NHS if the doctor thinks it is needed. The vaccine has reduced the incidence of chickenpox in the USA
Immunisation for older people
The vaccine against the varicella-zoster virus has been shown in large studies to be effective in reducing the risk of older people developing shingles. The vaccine has been shown to be safe with very few side-effects.
In the UK, there is a shingles vaccination programme for people aged 70 and 79. The programme began in September 2013.
Further help & information
Dr Tim Kenny
Dr Colin Tidy
Prof Cathy Jackson