Postherpetic neuralgia is a painful condition that affects the nerve fibers and skin. It is a complication of shingles, and shingles is a complication of chicken pox.
If the pain caused by shingles continues after the bout of shingles is over, it is known as post-herpetic neuralgia (PHN). It is estimated that about 1 in 5 patients with shingles will go on to have PHN.
Neuralgia is neuropathic pain that occurs along the course of a nerve. It tends to happen when an irritation or damage to a nerve alters its neurological structure or function.
The sensation may be of intense burning or stabbing, and it may feel as if it is shooting along the course of the affected nerve.
Neuropathic pain comes from inside the nervous system. It is not caused by an outside stimulus, such as an injury. People often refer to it as a pinched nerve, or trapped nerve. The nerve itself sends pain messages because it is either faulty or irritated.
Treatment will depend on the type of pain as well as the patient’s physical, neurological, and mental health.
Postherpetic neuralgia can cause severe pain in people who have had shingles.
Painkillers: These may include tramadol (Ultram) or oxycodone (OxyContin). There is a small risk of dependency.
Anticonvulsants: The pain of PHN can be lessened with anticonvulsants, because they are effective at calming nerve impulses and stabilizing abnormal electrical activity in the nervous system caused by injured nerves. Gabapentin, or Neurontin, and pregabalin, also known as Lyrica, are commonly prescribed to treat this type of pain.
Steroids: A corticosteroid medication can be injected into the area around the spinal cord. Steroids should not be used until the shingles pustular skin rash has completely disappeared.
Lidocaine skin patches: Lidocaine is a common local anesthetic and antiarrhythmic drug. Applied to the skin, it can relieve itching, burning, and pain from inflammation. The patches can be cut to fit the affected area.
Antidepressants: These affect key brain chemicals, such as serotonin and norepinephrine, which influence how the body interprets pain. Examples of drugs that inhibit the reuptake of serotonin or norepinephrine are tricyclic antidepressants, such as amitriptyline, desipramine (Norpramin), nortriptyline (Pamelor), and duloxetine (Cymbalta).
Transcutaneous electrical nerve stimulation (TENS)
This treatment involves placing electrodes over the areas where pain occurs. These emit small electrical impulses. The patient turns the TENS device on and off as required.
Some people find that TENS relieves pain, while others do not. Its effectiveness has not been confirmed by research.
Spinal cord or peripheral nerve stimulation
These devices offer a safe, efficient, and effective way to relieve many types of neuropathic pain conditions. Similar to TENS, they are implanted under the skin along the course of peripheral nerves. Before implantation, doctors do a trial run using a thin wire electrode to determine patient response.
The spinal cord stimulator is inserted through the skin into the epidural space over the spinal cord. The peripheral nerve stimulator is placed under the skin above a peripheral nerve. As soon as the electrodes are in place, they are switched on to administer a weak electrical current to the nerve.
Experts believe that by stimulating the non-painful sensory pathway, the electrical impulses trick the brain into “turning off” or “turning down” the painful signals, resulting in pain relief.
After the signs of shingles have gone, nerve pain may remain.
Symptoms are usually limited to the area of skin where the shingles outbreak first occurred and may include:
occasional sharp burning, shooting, jabbing pain
constant burning, throbbing, or aching pain
extreme sensitivity to touch
extreme sensitivity to temperature change
In rare cases, if the nerve also controls muscle movement, there may be muscle weakness or paralysis.
Symptoms may make it hard to carry out some daily activities, such as bathing or dressing. PHN may also cause fatigue and sleeping difficulties.