Meralgia paresthetica

Background

• Entrapment of the lateral femoral cutaneous nerve usually in the inguinal canal

Etiology

• Intrapelvic (pregnancy, enlarging mass, aneurysm)
• Extrapelvic (trauma, tight garment or belt, obesity)
• Systemic (DM)

Clinical Features

• Numbness and pain of anterolateral thigh
• Pelvic compression test
  • Turn patient on side
  • Compress pelvis
  • If symptoms are relieved after 30s of lateral compression diagnosis is confirmed

Differential Diagnosis

Hip pain

Acute Trauma

• Femur fracture
  • Proximal
    • Intracapsular
      • Femoral head fracture
      • Femoral neck fracture
    • Extracapsular
      • Intertrochanteric femur fracture
      • Trochanteric femur fracture
  • Shaft
    • Mid-shaft femur fracture (all subtrochanteric)
• Hip dislocation
• Pelvic fractures
  • Acetabular pelvic fractures
  • Open book pelvic fracture
  • Straddle pelvic fracture
  • Pelvic avulsion fracture

Chronic/Atraumatic

• Hip bursitis
• Psoas abscess
• Piriformis syndrome
• Meralgia paresthetica
• Septic arthritis
  • Septic arthritis of the hip (peds)
• Obturator nerve entrapment
• Avascular necrosis of hip

Thigh Numbness

• L3/L4 radiculopathy
• Lumbosacral plexopathy
• Femoral neuropathy

Evaluation

• History - tight fitting clothes/ belts, recent weight gain, worse with valsalva or prolonged walking
• Neurologic exam - diminished sensation in the distribution of the lateral femoral cutaneous nerve
  • Rule out weakness or reflex changes that would suggest an alternative diagnosis
• Imaging - generally not necessary, unless atypical symptoms or concern for radiculopathy/ plexopathy
• Nerve conduction studies (NCS)/ Electromyography (EMG) - generally not necessary, unless atypical symptoms or concern for radiculopathy/ plexopathy

Management

• NSAIDs
• Weight loss
• Corticosteroid injection