Meralgia paraesthetica

Meralgia paraesthetica is a problem with a nerve (lateral femoral cutaneous nerve) that provides sensation to the outer thigh.

This nerve does not connect to any muscles, only the skin on the outer thigh, that is why it is called a cutaneous nerve which means skin. The nerve runs from the lower back where it starts, over the brim of the pelvic bone and down the outer thigh. Along the way, it can be compressed or knocked causing damage to the nerve.

This leads to a burning sensation on the outer thigh and may be associated with tingling or numbness.

This problem can usually be diagnosed by a clinical assessment in the doctor’s office but nerve conduction studies may be required to confirm the diagnosis.


Symptoms

Symptoms of meralgia paraesthetica include the following:

  • A painful, burning sensation on the outer aspect of the thigh is the hallmark of this condition
  • A sensation of numbness, tingling or pins and needles may be associated with the burning pain
  • The problem is usually present on one side only. However, they may be on both sides in up to 20% of cases.
  • The area of affected skin may be more sensitive to light touch than unaffected areas
  • Walking or standing may aggravate the symptoms; sitting tends to relieve them

Causes

Meralgia paraesthetica may be caused by anything that creates sustained pressure on the nerve, particularly where it crosses the brim of the pelvis. This is because the nerve is compressed against the hard bone leading to injury of the nerve. Situations that can cause this include the following:

  • pregnancy
  • tight clothing – especially belts
  • obesity
  • tool belts worn by carpenters
  • utility belts worn by policemen, and body armor worn by soldiers
  • certain activities that require the hips to be bent for long periods such as squatting low for prolonged periods

Another cause of meralgia paraesthetica is sustaining a knock or blow to the pelvic brim which compresses the nerve causing the same kind of damage.

Risk Factors

The following situations are risk factors for developing meralgia paraesthetica

  • diabetes: nerve problems like meralgia paraesthetica are common in people with long standing diabetes. Due to the blood supply being reduced to the nerve, less force is required to cause damage to the nerve
  • obesity: pressure on the pelvic brim where the nerve runs can be caused by obesity
  • pregnancy: with the enlarging uterus, pressure can be applied to the brim of the pelvis leading to compression of the nerve

Investigations

This problem can usually be diagnosed by a clinical assessment in the doctor’s office by taking a thorough history, assessing any risk factors and testing the nerve to see if it is functioning properly.

If any doubt remains, a nerve conduction study can be carried out which will confirm the diagnosis. This is a test that assesses how well signals are transmitted down a particular nerve.

Complications

Meralgia paraesthetica usually resolves without any problems. The pain in the outer thigh usually disappears over time, but there may be residual numbness in the affected area. This numbness may persist for many years.

Treatment

Most patients with meralgia paraesthetica will have mild symptoms that respond well to conservative management. Removing the cause of the pressure on the nerve is the best therapy. This may involve:

  • resting from an aggravating activity
  • losing weight
  • wearing loose clothing
  • avoiding using a tool belt

If the pain is severe an injection of a corticosteroid mixed with a local anaesthetic may be given to relieve the symptoms.

In rare cases that remain painful even after an injection, surgery is needed to release the nerve.

Seeking Advice

Your Family Doctor (GP)

Your Family Doctor will be able to diagnose and help treat your problem. He or she will be able to

  • tell you about your problem
  • advise you of the best treatment methods
  • prescribe you medications
  • and if necessary, refer you to Specialists (Consultants) for further treatment

Prevention

The following steps can be taken to prevent meralgia paraesthetica arising:

  • avoiding wearing tight fitting clothing, especially heavy belts
  • losing weight
  • ensuring diabetes, if present, is well managed