Meralgia paresthetica

Definition

Meralgia paresthetica is a condition characterized by numbness, tingling, or pain along the outer thigh.

Description

Meralgia paresthetica occurs when the lateral femoral cutaneous nerve, which supplies sensation to the outer part of the thigh, is compressed or entrapped at the point where it exits the pelvis. Usually, only one thigh is affected. Obese, diabetic, or pregnant people are more susceptible to this disorder. Tight clothing may exacerbate or cause the condition.

Demographics

Overweight individuals are more likely to develop meralgia paresthetica; men are more commonly affected than women. The disorder tends to occur in middle-aged individuals.

Causes and symptoms

Meralgia paresthetica is the result of pressure on the lateral femoral cutaneous nerve, and subsequent inflammation of the nerve. The point of pressure or entrapment is usually where the nerve exits the pelvis, running through the inguinal ligament. Being overweight, having diabetes or other risk factors for nerve disorders, wearing tight clothing or belts, previous surgery in the area of the lateral femoral cutaneous nerve, or injury (such as pelvic fracture) predispose individuals to meralgia paresthetica.

Symptoms of meralgia paresthetica include numbness, tingling, stinging, or burning pain along the outer thigh. The skin of the outer thigh may be particularly sensitive to touch, resulting in increased pain. Many people note that their symptoms are initiated or worsened by walking or standing.

Diagnosis

The diagnosis is usually evident based on the patient's description of symptoms and the physical examination. Neurological testing will usually reveal normal thigh-muscle strength and normal reflexes, but there will be numbness or extreme sensitivity of the skin along the outer aspect of the thigh.

Treatment team

Depending on its severity, meralgia paresthetica may be treated by a family medicine doctor, internal medicine specialist, neurologist , or orthopedic surgeon.

Treatment

Patients with meralgia paresthetica are usually advised to lose weight and to wear loose, light clothing. Sometimes medications (amitriptyline, carbamazepine , or gabapentin , for example) can ameliorate some of the symptoms. In patients with severe pain, temporary relief can be obtained by injecting lidocaine (a local anesthetic) and steroids (an anti-inflammatory agent) into the lateral femoral cutaneous nerve. In very refractory cases, surgery to free the entrapped lateral femoral cutaneous nerve may be required in order to improve symptoms.

Prognosis

Many cases of meralgia paresthetica resolve spontaneously, usually within two years of onset.

Resources

BOOKS

Pryse-Phillips, William, and T. Jock Murray. "Peripheral Neuropathies." In Noble: Textbook of Primary Care Medicine, edited by John Noble, et al. St. Louis: W. B. Saunders Company, 2001.

Verdugo, Renato J., et al. "Pain and temperature." In Textbook of Clinical Neurology, edited by Christopher G. Goetz. Philadelphia: W. B. Saunders Company, 2003.

PERIODICALS

Shapiro, B. E. "Entrapment and compressive neuropathies." Medical Clinics of North America 8, no. 3 (May 2003): 663–696

WEBSITES

National Institute of Neurological Disorders and Stroke (NINDS). NINDS Meralgia Paresthetica Disease Information Page. January 28, 2003 (June 3, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/meralgia_paresthetica.htm>.

Rosalyn Carson-DeWitt, MD