What Is Postherpetic Neuralgia?
Although the drugs used to treat shingles can lessen the severity and duration of the condition, approximately 20 percent of patients diagnosed with shingles later develop a painful chronic condition called postherpetic neuralgia (PHN). No known treatment exists that can definitely prevent the occurrence of chronic pain or PHN, though studies have shown the antiviral medications used to treat shingles may reduce the possibility of getting PHN in the future.
While the pain and discomfort of shingles usually lasts about a month, the pain and skin sensitivity of PHN can continue long after the shingles rash heals—in some cases for months or even years. This happens because the herpes-zoster virus damages the nerve fibers during the shingles infection.
The risk of developing postherpetic neuralgia increases with age. One in four people who develop shingles after the age of 55 develops PHN. About half of those who experience shingles at or after age 60 develop the condition, as do three out of four people who suffer an attack of shingles when they are age 70 or older.
The pain of postherpetic neuralgia can be sharp, piercing, throbbing, or stabbing, and may result in skin sensitivity that renders even the slightest touch intolerably painful. Typically, the pain of PHN is in the same area where the patient experienced the pain and rash of shingles. Some patients experience pain in smaller areas within the rash region, while others feel it in an area larger than the original rash site. Some patients describe it as deep and aching, an unbearable shooting pain, a sensation like fire under the skin or an electric shock.
In some PHN patients, even the pressure of a shirt, a gust of wind, slight changes in temperature, or combing one's hair is intensely painful. This type of pain and sensitivity can disrupt a person's life. Some PHN sufferers stop all normal activity for months, become socially isolated, and depressed.
Fortunately, the pain of PHN usually resolves gradually over time, and there are a number of treatment options to help until then. These include prescription medications, such as strong pain relievers containing opioids, antidepressants, and antiseizure medication. A promising new patch containing anesthetic lidocaine (Lidoderm patch) can provide reliev to those who haven't responded to other treatments or who don't want to take oral medication. There is also an over-the-counter capsaicin cream (Zostrix)that is derived from hot peppers, which can reduce the symptoms of postherpetic neuralgia. Most patients find relief from one or a combination of these drugs.
For more information on shingles and PHN, contact:
VZV Research Foundation
40 East 72nd Street
New York, NY 10021
phone: 212.472.7148 or 1.800.472.VIRUS
American Chronic Pain Association
PO Box 850
Rocklin, CA 95677
National Chronic Pain Outreach Association, Inc.
PO Box 274
Millboro, VA 24460