About Postherpetic neuralgia

Postherpetic neuralgia is a painful condition affecting your nerve fibers and skin. Postherpetic neuralgia is a complication of shingles, a second outbreak of the varicella-zoster virus, which initially causes chickenpox. During an initial infection of chickenpox, some of the virus remains in your body, lying dormant inside nerve cells. Years later, the virus may reactivate, causing shingles. Once reactivated, the virus travels along nerve fibers, causing pain. When the virus reaches your skin, it produces a rash and blisters. A case of shingles (herpes zoster) usually heals within a month. But some people continue to feel pain long after the rash and blisters heal — a pain called postherpetic neuralgia. A variety of treatments for postherpetic neuralgia exist, although you may not experience complete relief from pain. The symptoms of postherpetic neuralgia are generally limited to the area of your skin where the shingles outbreak first occurred. They may include:

  • Sharp and jabbing, burning, or deep and aching pain
  • Extreme sensitivity to touch and temperature change
  • Itching and numbness
  • Headaches

In rare cases, you might also experience muscle weakness or paralysis — if the nerves involved also control muscle movement.

Causes

Postherpetic neuralgia results when nerve fibers are damaged during an outbreak of shingles. Damaged nerves aren’t able to send messages from your skin to your brain as they normally do. Instead, the messages become confused and exaggerated, causing chronic, often excruciating pain that may persist for months — or even years — in the area where shingles first occurred. This complication of shingles occurs much more frequently in older adults. About 50 percent of adults older than 60 experience postherpetic neuralgia after shingles, whereas only 10 percent of all people with shingles do.

Treatment

Treatment for postherpetic neuralgia depends on the type of pain you experience. Possible options include:

  • Antidepressants. Your doctor may prescribe antidepressants for postherpetic neuralgia, even if you’re not depressed. These drugs affect key brain chemicals, including serotonin and norepinephrine, which play a role in both depression and how your body interprets pain. Doctors typically prescribe antidepressants for postherpetic neuralgia in smaller doses than they do for depression. Drugs that inhibit the reuptake of norepinephrine and serotonin — including tricyclic antidepressants, such as amitriptyline, desipramine (Norpramin), nortriptyline (Pamelor) and duloxetine (Cymbalta) — may not eliminate the pain. However, they can make it more tolerable.
  • Certain anticonvulsants. Medications for treatment of seizures also can lessen the pain associated with postherpetic neuralgia. These medications stabilize abnormal electrical activity in your nervous system caused by injured nerves. Doctors may prescribe gabapentin (Neurontin), pregabalin (Lyrica) or another anticonvulsant to help control burning and pain.
  • Injected steroids. Corticosteroid medications injected into the area around the spinal cord may help relieve the persistent pain of postherpetic neuralgia. This treatment is usually reserved until after the pustular skin rash associated with shingles has gone away.
  • Painkillers. Your doctor may prescribe painkillers such as tramadol (Ultram) or drugs containing oxycodone, either in short-acting formulations such as Percocet or in long-acting formulations such as OxyContin. However, these drugs are narcotics and can be addictive. Although this risk is generally low, discuss it with your doctor.
  • Transcutaneous electrical nerve stimulation (TENS). This treatment involves the placement of electrodes over the painful area. The electrodes deliver tiny, painless electrical impulses to nearby nerve pathways. You turn the TENS unit on and off as needed to control pain. Exactly how the impulses relieve pain is uncertain. One theory is that the impulses stimulate production of endorphins, your body’s natural painkillers. This treatment doesn’t work for everyone.
  • Spinal cord or peripheral nerve stimulation. These devices are similar to TENS, but are implanted underneath the skin. Like with TENS units, you can turn these units on and off as needed to control pain. Before the device is surgically implanted, doctors do a trial using a thin wire electrode. The trial is done to ensure that the stimulator will provide effective pain relief. The electrode is inserted through your skin into the epidural space over the spinal cord for a spinal cord stimulator or under your skin above a peripheral nerve in the case of a peripheral nerve stimulator. If a permanent stimulator is implanted, the stimulator’s pulse generator is placed under the skin, usually in the upper buttocks, but occasionally in other locations. Some areas, such as your chest, abdomen and some areas of your face, are less amenable to treatment using this method.
  • Lidocaine skin patches. These are small, bandage-like patches that contain the topical, pain-relieving medication lidocaine. These patches can be cut to fit the affected area. You apply the patches, available by prescription, directly to painful skin to deliver temporary relief. Don’t use patches containing lidocaine on your face.

In some cases, treatment of postherpetic neuralgia brings complete pain relief. But most people still experience some pain, and a few don’t get any relief. Although some people must live with postherpetic neuralgia the rest of their lives, most people can expect the condition to gradually disappear during the first three months. For about 10 percent to 20 percent of people with postherpetic neuralgia, the pain may persist for a year or more.

Prevention

Two vaccines may help prevent shingles and subsequent postherpetic neuralgia — the chickenpox (varicella) vaccine and the shingles (varicella-zoster) vaccine. If you haven’t had chickenpox: Chickenpox vaccine The varicella virus vaccine (Varivax) has become a routine childhood immunization to prevent chickenpox. It’s also recommended for older kids and adults who’ve never had chickenpox. Though the chickenpox vaccine doesn’t guarantee you won’t get chickenpox or shingles, it can reduce your chances of complications and reduce the severity of the disease. If you’ve already had chickenpox: Shingles vaccine The varicella-zoster vaccine (Zostavax) can help prevent shingles in adults age 60 and older who’ve had chickenpox. Like the chickenpox vaccine, the shingles vaccine doesn’t guarantee you won’t get shingles. But this live attenuated virus vaccine will likely reduce the course and severity of the disease and reduce your risk of postherpetic neuralgia. One study found the vaccine reduced the number of cases of postherpetic neuralgia by two-thirds. The shingles vaccine is given as a single injection, usually in the upper arm. It’s only used as a prevention strategy, however. It’s not intended to treat people who already have the disease. Common side effects include redness, pain and swelling at the needle site, itching and headache. This shingles vaccine isn’t recommended if you:

  • Have ever had a life-threatening allergic reaction to gelatin, the antibiotic neomycin or any other component of the shingles vaccine
  • Have a weakened immune system from HIV/AIDS or another disease that affects your immune system
  • Are receiving medical treatments such as steroids, radiation and chemotherapy
  • Have a history of bone marrow or lymphatic cancer
  • Have active, untreated tuberculosis

If you are mildly ill, such as with a cold, it’s OK to get the vaccine. However, if you’re moderately or severely ill, wait until you feel better before getting the vaccine.

Self-care

After talking with your doctor, you may find the following over-the-counter medications ease the pain of postherpetic neuralgia:

  • Capsaicin. This cream, made from the seeds of hot chili peppers, may relieve pain from postherpetic neuralgia. Capsaicin (Capzasin-P, Zostrix) can cause a burning sensation and irritate your skin, but these side effects usually disappear over time. Capsaicin cream can be very irritating if rubbed on unaffected parts of your body, such as in your eyes. Follow the application instructions carefully, including wearing gloves for application and washing your hands thoroughly after applying.
  • Topical analgesics and anesthetics. Aspirin mixed into an absorbing cream or nonprescription-strength lidocaine cream may reduce skin hypersensitivity. Don’t apply cream containing lidocaine to your face. Your doctor may also recommend using a cream containing other medications.