What can help my long-term shingles pain?

Conditions Expert Dr. Otis Brawley Chief Medical Officer,
American Cancer Society

Expert answer

The varicella-zoster virus (VZV) causes "chicken pox," and later in life comes out of nerves as a rash known as herpes zoster, or "shingles." Most cases of acute shingles are self-limited in time and location on the body. It is common for the zoster rash and the pain from it to be on a long line on the body paralleling a nerve. The pain of shingles can be tremendous, interfering with normal activities, sleep and even appetite. Some patients continue experiencing the pain for months or years after the resolution of the rash. This long-term pain is known as post-herpetic neuralgia, or PHN.

The older the patient with the herpes zoster rash, the greater the risk of PHN. In some series, 7 percent of people in their 60s with zoster experience PNH and 20 percent of people in their 70s develop it after a zoster rash. There are things you can do to prevent PNH.

They include:

• There is a shingles vaccine. There is evidence that it lowers risk of shingles, and for those who do get the vaccine and later do develop shingles, there is evidence that they have a disease of less intensity that is less likely to progress to PHN. The vaccine has no role in PHN once it is occurs, but it can prevent future zoster outbreaks.

• There are also some data to suggest that patients who get shingles and get early treatment with anti-viral therapy shorten the duration of the shingles outbreak and decrease risk of PNH. Acyclovir, valacyclovir and famciclovir are oral medications used for this.

• Certain tricyclic anti-depressants (amitriptyline or nortriptyline) and anti-seizure medications (gabapentin, phenytoin, carbamazepine) have been given during the initial rash and appear in clinical study to decrease risk of PNH. (These drugs were initially used for treatment of depression or seizures and have been shown to be good at treating pain.)

Some advocate steroid treatments be given during the rash with the intent of preventing PNH. All clinical trials to assess this have failed to provide any evidence that steroids prevent PNH.

For those unfortunate to get PNH, studies show that steroid injections in the nerve root are a useful treatment. Other treatments used to relieve the pain of PHN include: the tricyclic antidepressants named above, the anti-seizure drugs named above, narcotics, capsaicin, topical lidocaine, cold therapy (cryotherapy) and disruption of the affected nerve. The affected nerve can be disrupted through injection of a drug at the nerve root or the nerve can be surgically cut. Mild pain medicines, such as aspirin, acetaminophen or ibuprofen just do not work.

Capsaicin is a fascinating drug. It is a topical cream that is available without prescription. It is an extract of cayenne pepper that burns as it is applied to the skin. It can cause several hours of relief from PNH and other forms of chronic pain such as diabetic neuropathy.

Post herpetic neuralgia can be quite difficult to treat. A patient may benefit from a trial of several of the treatments above, singularly or in combination. This has to be done at the direction of an experienced physician. Amazingly, many with PNH wake up one morning and after six months to a year of pain it has just gone away overnight.