Post-herpetic neuralgia is a form of chronic face pain after an attack of shingles on the face or torso. The type of pain that occurs with post-herpetic neuralgia is called neuropathic pain.
People with post-herpetic neuralgia usually experience a burning, aching or throbbing pain that is often accompanied by extreme tenderness. People might find that the wind blowing against their face or the brush of clothing or bedclothes is unbearable. Although people experience extreme tenderness in the affected areas, the general sensitivity of their skin is reduced.
What is shingles?
The medical name for shingles is herpes zoster. Shingles is caused by the chicken pox virus which most people get as a child. Shingles usually affects older people. It occurs when the virus, which has been in the body for many years without causing any symptoms, suddenly attacks one nerve in the skin. It most commonly affects a nerve on the upper body but it can affect nerves in the head and face. It only affects one side of the face.
Shingles can begin with a dull pain in the skin on the face. For most people, this is followed a few days later by a weeping rash. The rash usually clears up within a few weeks. This can be helped by certain drugs such as acyclovir and antidepressants. Some people are left with scarring but the majority of people find that the pain settles down and the rash disappears without leaving any scars.
How does shingles cause post-herpetic neuralgia?
The chicken pox virus damages the nerve and the area of skin supplied by that nerve goes partly numb. People experience pain is this area. The pain happens because the nerve continues to send pain signals to the brain.
Who gets post-herpetic neuralgia?
Anyone who has had shingles can get post-herpetic neuralgia, although it is very rare in younger adults. Post-herpetic neuralgia mainly occurs in people aged 65 years and older. Around 100,000 people develop post-herpetic neuralgia on some part of their body each year in the UK. Only a small number of them will develop the condition in the face.
What are the treatments for post-herpetic neuralgia?
If people are still experiencing face pain a month after the shingles rash has disappeared their GP should prescribe medication. This is because medication is more effective when it is taken in the early stages of post-herpetic neuralgia. Ordinary pain relief drugs usually have very little effect on post-herpetic neuralgia.
The main drugs used to treat post-herpetic neuralgia are amitriptyline or nortriptyline. These drugs are more commonly used to treat depression but they can have a very powerful effect on certain forms of nerve pain. For some people, they can reduce the pain by 30 per cent. It might take two to three weeks before they begin to provide any pain reduction. People might need to take these drugs for several months.
Other medicines prescribed to treat post-herpetic neuralgia include creams and lotions. These act as local anaesthetics and numb the area. There are also patches that contain an anaesthetic (for example, lidocaine). The patches look like regular plasters.
Surgical procedures to interrupt the nerve (used to treat people with trigeminal neuralgia) are never effective in the treatment of post-herpetic neuralgia.
The National Institute for Health and Clinical Excellence (NICE) have issued guidelines on the treatment of neuropathic pain conditions such as post-herpetic neuralgia.