Postherpetic Neuralgia
Pain After Shingles

Postherpetic neuralgia is a pain that persists in some people who have had shingles. It often eases and goes in time. Medication can often ease the pain.

What is postherpetic neuralgia?

Postherpetic neuralgia (PHN) is a nerve pain (neuralgia) that persists after a shingles rash has cleared. If the pain goes, but then returns at a later date, this too is called PHN.

Shingles is an infection of a nerve, and causes a typical rash. It is caused by the varicella-zoster virus. About 1 in 5 people have shingles at some time in their life. Shingles can occur at any age, but it is most common in people aged over 50. Most people with shingles have pain, but the pain usually eases soon after the rash clears. PHN is pain that persists. (See separate leaflet called 'Shingles' for details about shingles.)

PHN is unusual in people aged under 50, and if it does occur it tends to be mild. PHN is more likely to develop, and is more likely to be severe, in people aged over 60. About 1 in 4 people aged over 60 who have shingles develop PHN that lasts more than 30 days.

PHN causes pain on and around the area of skin that was affected by the shingles rash. The pain is mild or moderate in most cases. However, the pain is severe in some cases.

The pain is usually a constant, burning, or gnawing pain. In addition, or instead of this, you may have sharp or stabbing pains that come and go. The affected area of skin is often very sensitive. Even slight touch may cause pain such as the rubbing of clothes or a draught of air on the affected area. You may also have reduced sensation to touch, and be itchy over the affected area.

Shingles causes inflammation of the nerve. Pain can be expected whilst the rash and inflammation occur. However, it is not clear why some people continue to have pain when the inflammation has gone. It is thought that some scar tissue next to the nerve, or in the nearby part of the spinal cord, may be a factor. This may cause pain messages to be sent to the brain.

Without treatment, PHN typically eases gradually and goes. In about 5 in 10 people with PHN, symptoms are gone by three months. However, without treatment, about 3 in 10 people with PHN still have pain after a year.

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), or by having a cool bath. Some people find that putting several layers of 'cling film' over the affected area of skin helps. This allows clothes to slide over the skin without irritating.

Painkillers
Paracetamol, or paracetamol combined with codeine, may give some relief. Painkillers are best taken regularly to keep 'on top of the pain' rather than now and then. However, if painkillers do not help then see your doctor about trying an antidepressant or anticonvulsant medicine.

Antidepressant medicines
An antidepressant medicine in the 'tricyclic' group is a common treatment for PHN. It is not used here to treat depression. Tricyclic antidepressants ease neuralgia (nerve pain) separately to their action on depression. There are several tricyclic antidepressants, but amitriptyline is the one commonly used for nerve pain. Pain is stopped, or greatly eased, in up to 8 in 10 cases of PHN treated with amitriptyline. Imipramine and nortriptyline are other tricyclic antidepressants which are sometimes used to treat PHN.

A tricyclic antidepressant will usually ease the pain within a few days, but it may take 2-3 weeks. It can take several weeks before you get maximum benefit. Some people give up on their treatment too early. It is best to persevere for at least 4-6 weeks to see how well the antidepressant is working. If an antidepressant works, it is usual to take it for a further month after the pain has gone or eased. After this, the dose is gradually reduced and then stopped. You should re-start the antidepressant quickly if the pain returns.

Tricyclic antidepressants sometimes cause drowsiness. This often eases in time. To try and avoid drowsiness, a low dose is usually started at first, and then built up gradually if needed. A dry mouth is another common side-effect. Frequent sips of water may help with a dry mouth.

Anticonvulsant medicines
An anticonvulsant is an alternative to an antidepressant. For example, gabapentin or carbamazepine. (These medicines are commonly used to treat people with epilepsy but they have also been found to ease nerve pain.) An anticonvulsant can stop nerve impulses causing pains separate to its action on stopping convulsions.

Sometimes both an antidepressant and an anticonvulsant are taken if either alone does not work very well.

Capsaicin cream
This is sometimes used to ease pain if the above medicines do not help, or cannot be used because of problems or side-effects. Capsaicin is thought to work by blocking nerves from sending pain messages. Capsaicin cream is applied 3-4 times a day. Wash your hands immediately after applying it. It can cause an intense burning feeling when it is applied. In particular, if it is used less than 3-4 times a day, or if it is applied just after taking a hot bath or shower. (However, this side-effect tends to ease off with regular use.) Capsaicin cream should not be applied to broken or inflamed skin. It is therefore not suitable for use during an episode of shingles (only on healthy skin which is painful due to postherpetic neuralgia).

Treatment for itch
Some people have a severe itch with PHN. This is difficult to treat. An antihistamine taken at bedtime may help you to sleep better and reduce the scratching that you may do in the night (which may then make the itch less severe the following day).

Other treatments
Other treatments may be tried if the above treatments have not worked. These include various soothing or anaesthetic creams, injections, bio-feedback, transcutaneous nerve stimulation (TENS), ultrasound, and other techniques. These treatments are usually only advised under the supervision of a specialist in a pain clinic.

© EMIS and PIP 2005   Updated: September 2005   PRODIGY Validated