What is post-zoster neuralgia?
Post-zoster neuralgia is a disorder in which there is very severe pain in a nerve after a previous history of shingles. So it is ultimately caused by the herpes viruses that remain in the body for years after chickenpox and can damage nerves. If reactivated, shingles develops, with typical rashes.
These heal in about 90% of cases. If this does not happen, post-zoster neuralgia occurs, which is ultimately based on permanent damage to the nerves by the viruses. If the pain is treated adequately, the symptoms sometimes disappear completely.
Causes of Post-Zoster Neuralgia
Post-zoster neuralgia is a late possible secondary disease caused by the herpes viruses, also called varicella zoster viruses. These often cause chickenpox in childhood, which heals by itself. Afterwards, however, the viruses can remain in the body and migrate via nerve fibers into the cell bodies of nerves, for example in the area of the face or chest.
The viruses remain in these cell bodies for decades and can, for example, be reactivated if the body’s immune system is weakened. Then they can “break out” again, so to speak, and cause the disease of shingles. This leads to painful blisters in the supply area of the nerve in which they remain.
Shingles heals in about 90% of all those affected. However, permanent damage to the nerves can also occur. These occur mainly in older people, whose immune system is usually somewhat weaker. This permanent nerve damage then manifests itself as post-zoster neuralgia. The risk factors therefore include:
- Weakened immune system
- High age
- Therapy against the viruses started too late
Diagnosis
The diagnosis of post-zoster neuralgia in all cases includes a physical examination and a detailed doctor-patient consultation in order to establish the relevant history of the herpes virus. Furthermore, an examination of the cerebral fluid can provide information about the viruses still in the body. Depending on the severity, an MRI of the back may also be useful. In this case, the area of the spinal canal can be searched for inflammation, which can provide information about the localization of the viruses.
