FAQs on Post-herpetic Neuralgia

Post-herpetic neuralgia (PHN) is a neuropathic pain condition that occurs following an outbreak of shingles (varicella zoster virus). This virus causes chickenpox, and it can lie dormant in the body’s nerve cells for years.

What causes post-herpetic neuralgia?

During an infection with chickenpox, the varicella virus remains in the body and lies dormant in the nerve cells. Years later, illness, advanced age, decreased immune function, and certain medications can reactivate the virus, causing an outbreak of shingles on one side of the body. The rash can occur on the face, arms, legs, or trunk. It is most always unilateral (on one side), and the chest region is most often affected. Post-herpetic neuralgia develops when the rash subsides but the pain continues.

What are the symptoms and signs of post-herpetic neuralgia?

Neuralgia is limited to the area on the skin near where the rash occurred. Symptoms include:

  • Sharp, burning, jabbing, and aching pain
  • Extreme sensitivity to touch and temperature changes
  • Itching and numbness
  • Headaches

What causes post-herpetic neuralgia?

Post-herpetic neuralgia occurs when nerve fibers are damaged from the varicella virus. After a shingles outbreak, the nerves continue to send pain signals to the brain, even when the rash subsides. Less than 10% of people age 60 and younger develop PHN following shingles, but almost half of the elderly population do.

How is PHN diagnosed?

There is no medical test used to diagnosed post-herpetic neuralgia. Doctors rely on symptoms and medical history to make the diagnosis. You should seek treatment when you first have a shingles outbreak. Treating the varicella virus within three days of the rash will usually prevent PHN. Oral antiviral drugs are used to suppress the virus and make the outbreak less severe.

How is post-herpetic neuralgia treated?

The pain management specialist will use a combination of treatments for PHN. Your options include:

  • Topical lidocaine patches – Lidoderm skin patches are small, bandage-like patches that contain a topical anesthetic. This medication is delivered to the painful region to block pain signal transmission.
  • Antidepressants – Certain antidepressants are prescribed for PHN because these drugs affect brain chemicals (norepinephrine and serotonin), which play a role in both depression and how the body reacts to pain.
  • Anticonvulsants – Drugs like Neurontin and Lyrica control burning nerve pain. These medicines stabilize abnormal electrical activity in the nervous system, which is caused by injured nerves.
  • Nerve blocks – The doctor can inject a long-acting anesthetic and/or neurolytic agent onto the affected nerves to block pain signal transmission.
  • Pain relievers – The doctor may prescribe short-term pain medications, such as Ultram, oxycodone, or hydrocodone.
  • Transcutaneous electrical nerve stimulation (TENS) – Electrodes are placed on the skin and wires run to a device worn outside the body. Mild electric current is sent to the electrodes, which interfere with pain signals going from the affected region up the spinal cord and to the brain.
  • Intrathecal pump implant – The intrathecal pump implant, a pain pump, provides potent medicines into the space around the spinal cord. This allows medications to bypass the gastrointestinal tract. The doctor surgically implants a small device into the abdomen, and a catheter runs from the device to the spinal column.