Post Herpetic Neuralgia (PHN)
What is Post Herpetic Neuralgia (PHN)?
PHN is persistent nerve pain following a shingles outbreak which is along the same distribution as the initial shingles rash.
What are the symptoms of Post Herpetic Neuralgia?
The symptoms are generally felt on or around where the shingles outbreak occurred and may include burning, sharp and/or deep pain that lasts three months or longer after the shingles are gone. There is a sensitivity to light touch and possibly itching or numbness in the affected area.
What causes Post Herpetic Neuralgia?
The virus that originally causes chickenpox lies dormant in the body. When the virus is “woken up” through medications, stress, or immune suppression which can occur with common illnesses, a shingles outbreak occurs. Once the shingles are healed, there is susceptibility to PHN. This is a result of nerve fibers becoming damaged by the shingles outbreak, causing chronic pain.
How is Post Herpetic Neuralgia diagnosed?
A diagnosis of PHN is based on physical exam where a dermatomal rash or pain in dermatomal pattern.
What treatments are available for Post Herpetic Neuralgia?
Over the counter pain relievers such as aspirin or ibuprofen; topical creams and patches; antidepressants, anti-seizure medication, as well as specific injections such as nerve root blocks and epidural injections which target the affected nerves.