Neuralgia is pain that follows the path of a nerve.

See also: Trigeminal neuralgia

Causes of neuralgia include:

• Certain drugs
• Chemical irritation
• Chronic renal insufficiency
• Diabetes
• Infections, such as shingles, syphilis, and Lyme disease
• Porphyria
• Pressure on nerves by nearby structures (for instance, tumors)
• Swelling and irritation (inflammation)
• Trauma (including surgery)

In many cases, the cause is unknown.

Trigeminal neuralgia is the most common form of neuralgia. A related but uncommon neuralgia affects the glossopharyngeal nerve, which provides feeling to the throat.

Neuralgia is most common in elderly people, but it may occur at any age.

• Impaired function of affected body part due to pain, or muscle weakness due to motor nerve damage
• Increased sensitivity of the skin or numbness of the affected skin area (feeling similar to a local anesthetic, such as a Novocaine shot)
• Pain along the path of a specific nerve
• Pain located anywhere, usually on or near the surface of the body
  • In the same location for each episode
  • Sharp, stabbing pain that comes and goes (intermittent) or constant, burning pain

Any touch or pressure is felt as pain. Movement may also be painful.

An exam may show:

• Abnormal sensation in the skin
• Loss of deep tendon reflexes
• Loss of muscle mass
• Lack of sweating (sweating is controlled by nerves)
• Tenderness along a nerve, often in the lower face and jaw and rarely in the temple and forehead
• Trigger points (areas where even a slight touch triggers pain)

A dental examination can rule out dental disorders that may cause facial pain (such as a tooth abscess). Other symptoms (such as redness or swelling) may help rule out conditions such as infections, bone fractures, or rheumatoid arthritis.

There are no specific tests for neuralgia, but the following tests may be done to find the cause of the pain:

• Blood tests to check blood sugar and kidney function
• Magnetic resonance imaging (MRI)
• Nerve conduction study with electromyography
• Spinal tap (lumbar puncture)

The goal of treatment is to reverse or control the cause of the nerve problem (if found), and provide pain relief. Treatment varies depending on the cause, location, and severity of the pain, and other factors. Even if the cause of the neuralgia is never identified, the condition may improve on its own or disappear with time.

The cause (if known) should be treated. This may include surgery to remove tumors or separate the nerve from blood vessels or other structures that press on it. This can be done for some cases of carpal tunnel syndrome and trigeminal neuralgia.

Strict control of blood sugar may speed recovery in people with diabetes who develop neuralgia.

Medications to control pain may include:

• Antidepressant medications (amitriptyline, nortriptyline, duloxitine)
• Antiseizure medications (carbamazepine, gabapentin, lamotrigine or phenytoin) for trigeminal neuralgia pain
• Mild over-the-counter analgesics (aspirin, acetaminophen, or ibuprofen)
• Narcotic analgesics (codeine) for short-term relief of severe pain (however, these do not always work well)
• Topical creams containing capsaicin

Other treatments may include:

• Local injections of pain-relieving (anesthetic) drugs
• Nerve blocks
• Surgical procedures (such as ablation using radiofrequency, heat, balloon compression, or injection of chemicals) to reduce feeling in the nerve.

Unfortunately, these procedures do not guarantee improvement and can cause loss of feeling or abnormal sensations.

When other treatment methods fail, doctors may try motor cortex stimulation (MCS). An electrode is placed over the sensory cortex of the brain and is hooked to a pulse generator under the skin.

Treating shingles with antiviral medication may reduce the likelihood of developing postherpetic neuralgia. Postherpetic neuralgia may also be treated with oral (taken by mouth) prednisone.

Physical therapy may be helpful for some types of neuralgia, especially postherpetic neuralgia.

Most neuralgias are not life-threatening and are not signs of other life-threatening disorders. However, pain can be severe. For severe pain, be sure to see a pain specialist so that you can explore all treatment options.

Most neuralgias will respond to treatment. Attacks of pain usually come and go. However, attacks may become more frequent in some patients as they get older.

• Complications of surgery
• Disability caused by pain
• Side effects of medications used to control pain
• Unnecessary dental procedures before neuralgia is diagnosed

Contact your health care provider if:

• You develop shingles
• You have symptoms of neuralgia, especially if over-the-counter pain medications do not relieve your pain
• You have severe pain (see a pain specialist)

Treating related disorders such as diabetes and renal insufficiency may prevent some neuralgias. Strict control of blood sugar may prevent nerve damage in people with diabetes. In the case of shingles, there is some evidence that antiviral drugs can prevent neuralgia.

Shy ME. Peripheral neuropathies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 446.

Cutrer FM, Moskowitz MA. Headaches and other head pain. In: In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 421.