Post-herpetic neuralgia (Pain after zoster)

Postherpetic neuralgia results from shingles, which is related to chickenpox. After you have recovered from the chickenpox, the virus lies dormant in your nerves. At some point in time, it can reactivate and cause shingles. Although postherpetic neuralgia often improves over time, there are cases where the pain can remain debilitating.

What is postherpetic neuralgia?

• Postherpetic neuralgia is a complication of shingles
• The rash over a bandlike distribution commonly occurs over the trunk but can also be anywhere, including the head and neck or over the limbs
• If there is a rash over the face, this is a medical emergency and you will need to seek early treatment to prevent complications such as blindness
• When the rash goes away but the pain continues, this is postherpetic neuralgia and happens in 20% of people

What are the symptoms?

• Pain over the previous area of rash and blisters
• Pain may be described as burning and itching, aching or sharp
• Pain is worse when there is a change in temperature
• May have some associated numbness
• Your may feel tired, unable to sleep and have poor appetite, and feel depressed

What is the outcome of postherpetic neuralgia?

• It can last from weeks to months. Most resolve after 3 months.
•  In about 20%, the pain does not go away even after a year
• The pain can be annoying for some people, but it can be severe and excruciating for others

What are the risk factors for getting postherpetic neuralgia?

• Old age
• Having a severe rash
• A weak immune system due to disease or chemotherapy
• Pain and burning and tingling sensation right before the rash appears
• Not receiving medications within 3 days of the rash appearing

How to treat postherpetic neuralgia?

• Best way is to prevent shingles by taking a vaccine
• Antivirals can be given within the first 3 days of the rash
• Mild pain killers like acetaminophen, NSAIDs or etoricoxib can be tried first
• Lignocaine patches and capsaicin creams can also be tried
• Other medications include
  • Gabapentin and pregabalin
  • Amitriptyline and nortriptyline
  • Opioids
  • Injections to the affected area
• Pain procedures include:
  • Sympathetic blocks
  • Epidural steroid injections
  • Pulse radiofrequency of the affected dorsal root ganglion
  • Spinal cord stimulation
  • neurolysis (destruction) of the affected nerve