By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

“PHN” MEANS THE SHINGLES ARE GONE BUT THE PAIN LINGERS

Question: My husband had shingles a few weeks ago. The rash is gone, but he is having pain where the rash was. Is this normal after shingles? How long will it last? Does everyone with shingles get this pain? What can be done about it? He doesn’t want to bother the doctor about this.

Answer: First let me give you a little background on shingles. The herpes zoster virus that causes shingles is also responsible for the common childhood disease of chicken pox. After you recover from chicken pox, the virus doesn’t actually leave your body but enters a kind of hibernation stage. Then, years later -- usually after age 50 -- it can become active again and produce shingles.

After you’ve had a case of shingles and the characteristic rash disappears, a painful condition called post-herpetic neuralgia (PHN) can develop. It sounds like this is what has happened to your husband. The pain may be mild to severe and may persist or recur. There are several theories as to the exact mechanism underlying the pain, but no one has a sure answer yet.

Post-herpetic neuralgia seems to be more prevalent in the United States than in the rest of the world. In the U.S., 9 to 14 percent of people who have had shingles report suffering from PHN about a month after recovering from the infection. After three months, this drops to 5 percent, and at one year, it is down to 3 percent. A study in Iceland found that no patient under the age of 50 had severe pain at any time. In patients over 60, about 6 percent had pain at one month and 4 percent at three months.

The development of PHN is equally divided between the genders, but its incidence increases dramatically the older you become. If you are over age 60 when you contract shingles, you have about a 60 percent chance of developing PHN. At age 70, the odds increase to about 75 percent. There is also a relationship between the location of the shingles and the likelihood of developing PHN. If you have shingles on the face -- especially around the eye -- you are far more likely to get PHN than are those with shingles in the low back region. If your shingles are in the mid to upper back region, your PHN risk is moderate -- somewhere between these two extremes.

The good news is that while the pain may be quite severe, most cases of PHN resolve completely over time. Most PHN patients respond to medications for this problem. Tricyclic antidepressants such as amitriptyline and nortriptyline are commonly used for PHN and have a good response rate. Some anticonvulsants are approved by the Food and Drug Administration for treatment of PHN. Analgesic creams -- like those that contain capsaicin -- can help some people. SteroidS, antiviral agents and anesthetics have also been shown to work in certain cases. A very small minority of people do not respond to medical management and need surgical treatment aimed at blocking the nerve impulses that cause pain.

I would urge your husband to see his physician. He may be suffering needlessly for a condition that can be fully treated with a little medication.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.