DEPARTMENTS: Your Questions Answered
TYLER, KENNETH L.
Kenneth L. Tyler, M.D., is the Reuler-Lewin Family Professor and chairman of the department of neurology at the University of Colorado Denver.
Q I have shingles. What can I do to reduce the incidence of postherpetic neuralgia pain at home? Is there anything beside medication that can help ease the pain?
DR. KENNETH L. TYLER RESPONDS:
A Shingles (herpes zoster) is caused by the same virus as chickenpox, the varicella-zoster virus. The reactivation of this virus can cause a painful, blistering rash that's sometimes accompanied by numbness or itching. It has been estimated that nearly 20 percent of individuals will be affected by shingles during their lifetime, and that close to a million cases occur annually in the U.S.
Almost all people with shingles will experience some pain, but a portion of those affected will experience significant pain for an extended period of time. This is called post-herpetic neuralgia (PHN) and is most commonly defined as pain occurring for at least one month (sometimes beyond three months) after the shingles rash has healed. The risk of PHN increases with age and is uncommon in people under 50.
In 2006 the FDA approved live zoster vaccine for the prevention of shingles and PHN. During clinical trials it reduced the risk of shingles by more than 50 percent and of PHN by nearly two thirds. The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommends that people over 60 without an impaired immune system receive the vaccine.
If PHN has already developed, the treatment generally parallels those used for neuropathic pain. The most commonly used treatments include tricyclic antidepressants (amitriptyline, nortriptyline, desipramine); anti-epileptics (gabapentin and pregabalin); and analgesics (tramadol and opioids). Some topical medications have also shown benefit, including the xylocaine patch and capsaicin cream. Patients who fail to respond to these treatments may be candidates for more aggressive pain management strategies that include epidural steroid or anesthetic injections.
Some non-medicinal approaches to treatment of PHN include acupuncture and transcutaneous electrical nerve stimulation (the stimulation of nerves by an electrical current for therapeutic reasons). Unfortunately there are few clinical trials that demonstrate the effectiveness of these treatments either alone or in conjunction with medicinal treatments.