What is Postherpetic Neuralgia?
Postherpetic neuralgia is a complication of shingles, a viral infection that causes a painful skin rash. The condition is characterized by burning pain that lasts long after the shingles rash has faded. Early treatment of shingles can help lessen the likelihood of developing postherpetic neuralgia.
Causes of Postherpetic Neuralgia
The virus that causes chickenpox stays in your body for the rest of your life. The virus can reactivate and travel along the nerves to cause shingles as you become older or if your immune system is compromised, such as by drugs or chemotherapy. Damage to nerve fibers during a shingles infection causes postherpetic neuralgia (PHN). Nerve fibers in the afflicted area of the skin deliver excessive pain signals to the brain.
What are the Symptoms of Postherpetic Neuralgia?
Common signs and symptoms of postherpetic neuralgia include:
- Itching and numbness
- Allodynia (sensitivity to touch)
- You may have burning, stabbing, or aching discomfort
- Extreme sensitivity to temperature change
- Headaches
- Even after the rash has faded, severe pain persists for more than 1 to 3 months in the same location where the shingles appeared.
Diagnosis of Postherpetic Neuralgia
Your doctor will review your medical history and symptoms, including your history of shingles, and based on this a skin examination will be performed. In most cases, no tests are needed.
Treatment for Postherpetic Neuralgia
The treatment for postherpetic neuralgia is aimed at relieving symptoms and includes:
Lidocaine Skin Patches
These are small, bandage-like patches that contain lidocaine, a topical pain reliever. These patches can be tailored to only cover the affected area. It can help with itchiness, burning, and inflammation-related pain.
Capsaicin Skin Patches
These are high-concentration synthetic capsaicin patches applied at your doctor’s office to the painful areas for 60 minutes at a time after applying a numbing agent to the area. A single application can decrease pain for some people for up to three months. If the application is successful, it can be repeated every three months.
Anticonvulsants
Gabapentin and pregabalin are two anti-seizure drugs that can help with postherpetic neuralgia pain. These drugs help to control aberrant electrical activity in your nervous system, which is caused by damaged nerves.
Antidepressants
Nortriptyline, amitriptyline, duloxetine, and venlafaxine are antidepressants that influence critical brain chemicals that have a role in both depression and how your body processes pain. Antidepressants are frequently prescribed in lower doses for postherpetic neuralgia.
Opioid Painkillers
Some patients may require opioid-containing prescription pain relievers.
Steroid Injections
The region around the spinal cord affected by the virus can be injected with a corticosteroid drug. Steroids should not be administered until the pustular skin rash caused by shingles has entirely disappeared.
Transcutaneous electrical nerve stimulation (TENS)
This treatment entails placing electrodes over painful locations. Small electrical impulses are emitted by them to reduce pain symptoms. The patient controls the TENS device by turning it on and off as needed.
Prevention
The shingles vaccine can help to minimize your risk of shingles. In individuals 50 years of age and older, the recombinant herpes-zoster vaccination may be indicated to prevent shingles.