Neuralgia is severe pain that occurs along the course of a nerve. It tends to happen when an irritation or damage to a nerve alters its neurological structure or function.
People with postherpetic neuralgia (PHN) describe the sensation as one of intense burning or stabbing pain that may feel as if it is shooting along the course of the affected nerve.
Neuropathic pain and postherpetic neuralgia
Neuropathic pain is a pain that comes from inside the nervous system. It is not caused by an outside stimulus, such as an injury. People often refer to it as a pinched nerve, or trapped nerve. The nerve itself sends pain messages because it is either faulty or irritated.
People with neuralgia have neuropathic pain.
What Is postherpetic neuralgia?
Postherpetic neuralgia (PHN) is a persistent nerve pain that can occur as a result of shingles. Shingles is caused by the herpes varicella-zoster virus, the virus known to cause chickenpox. After a person recovers from chickenpox, the virus remains inactive in the nervous system.
Later in life, the herpes varicella-zoster virus may become reactivated, causing shingles. Shingles is an infection of a nerve and the area of skin around it. Usually the nerves of the chest and abdomen on one side of the body are affected.
If the pain caused by shingles continues after the bout of shingles is over, it is known as PHN. It is estimated that about 1 in 5 patients with shingles will go on to have PHN.
The nerve damage that is caused by shingles disrupts the proper functioning of the nerve. The faulty nerve becomes confused and sends random, chaotic pain signals to the brain. The patient feels these as a throbbing, burning pain along the nerve.
Experts believe that shingles causes scar tissue to form next to the nerves, creating pressure. This causes the nerves to send inaccurate signals, many of them pain signals, to the brain. It is unclear why some patients go on to develop PHN.