History and Physical Examination
A thorough medical and surgical history is important for the correct diagnosis of meralgia paresthetica, including questioning the patient about the possibility of any relevant trauma. [15, 16, 17]
The physical examination in patients with meralgia paresthetica is remarkable for the findings of altered sensation in the anterolateral thigh, including pain, numbness, burning, hyposensitivity, and tingling. Typically, the symptoms begin insidiously and do not extend below the knee. The pain tends to be sharp or burning but also may be dull or achy.
The examiner should also consider whether any abnormal postures or movements are contributing to the patient's symptoms. Prolonged standing and standing up from a seated position may aggravate the condition.
Motor and reflex examination findings should be normal. If the patient has evidence of motor weakness or low back pain, other diagnoses should be considered because the lateral femoral cutaneous nerve (LFCN) is purely sensory, and a neurologic examination should be conducted.
Trigger points, lumbar radiculopathy, plexopathy, and hip pathology can masquerade as meralgia paresthetica. A positive Tinel sign finding may be elicited near the anterior superior iliac spine (ASIS).
Meralgia paresthetica may affect a very large region of the anterior and lateral thigh. However, the involved area can vary significantly, depending on the site of entrapment and anatomic variations of the nerve. In a large case series [10] of 120 patients, 88 (73%) had symptoms solely in the lateral aspect of the distal thigh. In 11 of the 120 patients (9.2%), the anterior aspect of the thigh was exclusively involved.
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The lateral femoral cutaneous nerve provides sensory innervation to the anterolateral thigh. Courtesy of Essentials of Physical Medicine and Rehabilitation, Hanley & Belfus Publishers, 2001, used with permission.
