Postherpetic neuralgia is a complication of shingles and a persistent nerve pain, which is caused by the chickenpox (i.e herpes zoster) virus, occurring at the site of a previous attack of a condition called shingles. Most cases of shingles clear up within a few weeks, but if the pain lasts long after the shingles rash and blisters have disappeared, it is called postherpetic neuralgia. Postherpetic neuralgia affects the nerve fibers and skin, and the burning pain associated with postherpetic neuralgia can be severe enough to interfere with sleep and appetite.
The risk of postherpetic neuralgia increases with age, primarily affecting people older than 60. The area affected also makes a difference. When shingles occurs on the face, for example, the likelihood of postherpetic neuralgia is significantly higher than for other parts of the body.
Currently, there is no cure, but there are treatment options to ease symptoms. For most people, postherpetic neuralgia improves over time
The main symptom of post-herpetic neuralgia is continuous nerve pain in an area previously affected by shingles. The signs and symptoms of postherpetic neuralgia are generally limited to the area of the skin where the shingles outbreak first. The symptoms may include:
- Pain associated with postherpetic neuralgia;
- Sensitivity to light touch of clothing on the affected skin;
- Itching and numbness;
- Muscle weakness or paralysis.
Once a person has had chickenpox, the virus that caused it remains in the body for the rest of the life. As they grow older, the virus can reactivate. Sometimes this occurs when the body is stressed due to another infection or medications that suppress the immune system. The result is shingles. Postherpetic neuralgia occurs if the nerve fibers are damaged during an outbreak of shingles and therefore, not able to send messages from the skin to the brain as they normally do. Instead, the messages become confused and exaggerated, causing chronic excruciating pain that may persist for months.
PHN itself is a complication of shingles. Other complications of PHN include lifestyle changes where the patient may become addicted to pain medications, have an inability to have a normal lifestyle because of the constant pain. In a few cases of PHN, muscle weakness can be an additional complication.
There is no definite way to prevent post-herpetic neuralgia. Thus, antiviral medication will often be given early during an episode of shingles to help reduce the risk of complications such as post-herpetic neuralgia. Alternatively, a person can reduce the risk of post-herpetic neuralgia by having the shingles vaccination to try to prevent an attack of shingles occurring.