When the Pain PersistsIn some patients, the misery continues long after the rash has healed. Many of the 1 million people who develop shingles each year experience a complication called post-herpetic neuralgia (PHN). This term refers to pain that is present in the affected area for months, or even years, afterward. Although the acute pain of shingles and the chronic pain of PHN (called neuropathic pain) both originate in the nerve cells, their duration and the reaction to treatment is different.
Pain that occurs with the initial outbreak responds to treatment and is limited in duration. In contrast, PHN lasts longer, is difficult to treat and can be incapacitating. Furthermore, for unknown reasons, older people suffer more from this debilitating pain than younger people. In many individuals, the skin is so sensitive that clothing or even a passing breeze cannot be tolerated on the affected area. Described by PHN sufferers as agonizing, excruciating, and burning, the pain can result in an inability to perform daily tasks of living, and lead to loss of independence and, ultimately, depression and isolation.
"I would rather have ten babies than the pain I've endured for the past ten years," says 87-year-old Etta Watson Zukerman of Bethesda, Md., who has lost partial use of her right arm and hand due to nerve damage from PHN. "Nothing my doctor prescribed helped. I even went to a sports medicine specialist who recommended exercises. They didn't help either." Many PHN sufferers receive no relief at all, no matter what medications or therapies they use. And what works for one doesn't necessarily work for another.
Treating the PainDoctors use other methods to alleviate pain with varying degrees of success. "One of the relatively new medications that I'm enthusiastic about is the Lidoderm patch," says Veronica Mitchell, M.D., director of the pain management center and inpatient pain service at Georgetown University Hospital, Washington, D.C. "It's the transdermal form of lidocaine and it's been studied in the PHN population with very good results," adds Mitchell. "We prescribed the Lidoderm patch for a patient who had intolerable side effects with oral medications--and no relief, and she's had about a 50 percent-plus improvement in pain relief. It's one of my first-line therapies." The medication contained in this soft, pliable patch penetrates the skin, reaching the damaged nerves just under the skin without being absorbed significantly into the bloodstream. This means that the patch can be used for long periods of time without serious side effects.
Yet another method used to treat PHN is transcutaneous electrical nerve stimulation, or TENS. A device that generates low-level pulses of electrical current is applied to the skin's surface, causing tingling sensations and offering some people pain relief. One theory as to how TENS works is that the electrical current stimulates production of endorphins, the body's natural painkillers.
TENS is not for everyone. "TENS didn't help at all," says Einar Raysor of Rockville, Md. "I found there was a problem in fine-tuning the administration of the electrical current. Low doses of the electrical current didn't do anything for me. When the technician increased the current, it gave me a painful response. After this happened a couple of times, we dropped the treatment."
As a last resort, invasive procedures called nerve blocks may be used to provide temporary relief. These procedures usually entail the injection of a local anesthetic into the area of the affected nerves. "We have controversial results in the terms of the efficacy of nerve blocks," says Mitchell. "I do consider nerve blocks in treating PHN and I would perform them because there's some evidence that they work, but the real efficacy is to catch and treat the patient in the acute shingles phase. As PHN presents mostly in the elderly, and the older patient often is unable to tolerate some of the medications we use, I find nerve blocks useful in these cases."
Injection directly into the spine is another option for relief of pain that is not easily treated. A Japanese clinical study published in the New England Journal of Medicine found that an injection of the steroid methylprednisone combined with the anesthetic lidocaine reduced pain by more than 70 percent in one patient group compared with groups that received lidocaine alone or an inactive substance.