Meralgia paresthetica, which is also known as lateral femoral cutaneous nerve syndrome, is an entrapment or ‘pinching’ of the nerve that supplies sensation to the outer portion of the thigh. The lateral femoral cutaneous nerve becomes ‘entrapped’ as it passes under the ligament of the groin. Meralgia paresthetica is a condition in which the pressure on the nerve causes abnormal sensations of burning, pain and numbness in the distribution of this nerve, the outer and part of the front of the thigh.
Pressure on the lateral femoral cutaneous nerve, which supplies sensation to the upper thigh, may cause the following symptoms:
- Tingling and numbness in the outer (lateral) part of the thigh and
- Burning pain in or on the surface of the outer part of the thigh
These symptoms commonly occur only on one side of the body and may intensify after walking or standing.
Causes of Meralgia paresthetica include any condition that leads to an increase in pressure on the groin (usually associated with enlargement of the belly, such as in obesity or pregnancy). Meralgia paresthetica occurs when the lateral femoral cutaneous nerve, which supplies sensation to the surface of the outer thigh, becomes compressed, or ‘pinched.’ The lateral femoral cutaneous nerve is purely a sensory nerve and does not affect the ability to use the leg muscles.
In most people, this nerve passes through the groin to the upper thigh without trouble. In the situation of Meralgia paresthetica, the lateral femoral cutaneous nerve becomes trapped, which runs along the groin from the abdomen to the upper thigh. Common causes of this compression include any condition that increases pressure on the groin, including:
- Tight clothing, such as belts, corsets and tight pants;
- Obesity or weight gain;
- Wearing a heavy tool belt;
- Scar tissue near the inguinal ligament due to injury or past surgery;
- Nerve injury.