Patients commonly present with causalgia or burning pain, paresthesias, and hypesthesia over the upper lateral thigh. Symptoms are typically unilateral. Onset is usually subacute over days to weeks. Patients will typically point to or rub their outer thigh when describing symptoms and may have associated hair loss over the area secondary to repeated rubbing. Symptoms are typically unchanged from seating or standing position. However, symptoms may be associated with prolonged hip extension, such as during walking or rising from a seated position or from prolonged standing. Symptoms may also be relieved by hip flexion movements such as sitting. More rarely, symptoms are worsened by the valsalva maneuver or other causes of increased intra-abdominal pressure.[6]

Pertinent history includes tight-fitting clothing, recent trauma, recent weight gain, or pregnancy. The area of paresthesia or numbness is usually able to be distinguished on the exam. Symptoms are purely sensory since the LFCN does not contain motor fibers. 

Diagnostic maneuvers include the pelvic compression test in which the patient lies on their unaffected side and the examiner applies downward pressure on the patient’s ilium/pelvis for approximately 45 seconds. A test is positive if symptoms are reduced and has a reported sensitivity and specificity of 95% and 93%, respectively. Findings not associated with meralgia paresthetica include motor deficits, abnormal lower extremity reflexes, other sensory losses outside the LFCN distribution, or other neurologic symptoms.[7]

Diagnosis is based primarily on the history and physical exam, including purely sensory neurological changes without motor involvement in the anatomical location of the upper thigh. Evaluation should include a complete lower extremity neurologic examination. Deficiencies may be noted with pinprick and light touch over an approximately 10" x 6” oval area over the anterolateral thigh, however, deficiencies may also be noted more anteriorly or medially based on a patient’s specific anatomy. A lower extremity neurologic exam is normal with preserved deep tendon reflexes, motor strength, negative straight leg raise, and without sacroiliac, back, or hip abnormalities.[8]

Plain radiographs are not required in the diagnosis given a consistent history and physical exam. Electrodiagnostic studies for the LFCN produce variable results, are difficult to perform on overweight patients, and are typically not indicated in the diagnosis unless being used to rule out radiculopathy or plexopathy. Nerve blockade via injection of the lateral femoral cutaneous nerve (in which relief of pain confirms the diagnosis) is rarely used for diagnosis to distinguish from lumbosacral root pain.

The clinician may consider blood tests if a metabolic etiology is suspected. Imaging studies such as a pelvic x-ray may be indicated if a tumor or osteoarthritis is suspected. Likewise, an ultrasound or MRI may be ordered to investigate for a pelvic or retroperitoneal tumor.[2]

Meralgia paresthetica is a typically benign and self-limited condition with frequent spontaneous remission. Treatment focuses on patient reassurance and ways to reduce pressure and irritation over the nerve and groin region. This includes patient education that the condition is benign, counseling the patient to avoid tight-fitting garments, and discussion of weight loss if obesity is a contributing factor. Icing the area may be helpful in reducing local nerve irritation and inflammation of acute symptoms.[4]

Medications that may be helpful include NSAIDs, topical capsaicin, lidocaine, or tacrolimus for epidermal dysesthesia or cutaneous hypersensitivity.  Abdominal exercises may reduce pressure, but physical therapy is not a proven modality in treatment. Patients should be reexamined with a repeat neurologic exam if symptoms persist beyond 1 to 2 months with conservative treatments at which point anticonvulsants such as gabapentin, phenytoin, or carbamazepine may be helpful for treating the patient’s neuropathic pain.[4]

Anesthesiologist referral for a nerve block injection with a local anesthetic or glucocorticoid may also be considered.[9]

Surgery is rare but may be considered in chronic refractory cases, and is performed via either a surgical release procedure with decompression of the LFCN (which may include transposition of the LFCN approximately 2cm medially away from ASIS) or via a nerve transection procedure. The nerve decompression procedure preserves sensory function but is generally less successful than the sectioning procedure, which results in permanent anesthesia and is reserved only for patients with intractable pain. Approximately 80% of patients reported symptomatic improvement in a retrospective series of 167 patients who had a surgical nerve release or transection.[10] 

Several case reports have also noted improvement of refractory cases with pulsed radiofrequency nerve ablation of the lateral femoral cutaneous nerve, electroacupuncture, and kinesiology taping.[11]

Differential diagnosis of meralgia paresthetica may include lumbar radiculopathy, which is not commonly associated with localized symptoms and usually includes back pain. Other causes of anterolateral thigh pain to consider include abdominal masses, pelvic tumors, metastases in the iliac crest, avulsion fractures, hip osteoarthritis, and chronic appendicitis.[2]

Approximately 85% of patients with meralgia paresthetica report spontaneous recovery with conservative management. Cases due to iatrogenic causes typically improve within 3 months, and pregnancy-associated meralgia paresthetica typically improves after delivery.[2][4]

Complications of meralgia paresthetica are secondary to the surgical transection of the lateral femoral cutaneous nerve, which results in permanent anesthesia of the anterolateral thigh.[4]

Meralgia paresthetica is not a life-threatening disease, but it can result in significant morbidity if not diagnosed and treated appropriately. Interprofessional communication and patient education are key. The condition can be recognized and treated by multiple clinicians to include primary care, obstetricians/gynecologists, urologists, neurologists, and surgeons. A proper diagnosis can be challenging without a dedicated history taking, and physical exam and misdiagnosis can lead to unnecessary referrals and procedures. With adequate interprofessional communication and patient education, meralgia paresthetica can be diagnosed and treated in a timely fashion to improve patient outcomes.