Leg Pain - Differential Diagnosis Framework Bone/Joint Causes of Leg Pain: • Fracture • Arthritis • Gout/pseudogout • Trauma • Osteomyelitis • Patellofemoral pain syndrome • Arthritis • Popliteus tendinitis • Malignancy: Osteosarcoma, Ewing sarcoma • Legg-Calve-Perthes disease • Slipped capital femoral epiphysis • Bursitis • IBD • Psoriasis • Hepatitis • Hematoma Venous Causes of Leg Pain: • DVT • Varicose veins • Superficial thrombophlebitis Skin Causes of Leg Pain: • Infection: Cellulitis, Abscess, Necrotizing fasciitis • Inflammation: Wounds/ulcers, Edema Arterial Causes of Leg Pain: • PAD • Limb ischemia • Aortic/Iliac artery aneurysms Nerve Causes of Leg Pain: • Neuropathy (DM, Vit B12, B6, Cu deficiency etc) • Spinal stenosis/nerve compression • Sciatica • Tarsal tunnel syndrome, peroneal neuropathy • Sural nerve entrapment • Infections causing nerve damage: - Epidural abscess - Herpes zoster - HIV - Lyme disease Muscle Causes of Leg Pain: • Rhabdomyolysis • Compartment syndrome • Myositis/pyomyositis • Cramps (electrolyte imbalance) • Tendinitis • Repetitive strain injury • Iliotibial band syndrome • Shin splints • Hamstring strain • Piriformis syndrome Leg Pain Red Flags: • Trauma • Crush injury • DVT (Risks: Recent surgery, Smoking, Contraceptive pill, Immobilization) • Acute limb ischemia/cyanosis - Cool extremity - Prolonged capillary refill - Poor pulses - Hair loss- feet and legs - Brittle nails - Skin ulcers - Shiny skin • Inflammation/cellulitis/abscess • Compartment syndrome - History of blunt trauma, crush - Rigorous exercise - Excessive training 1) Pain 2) Pallor-bruising 3) Paralysis 4) Paresthesia 5) Pulselessness 6) Poikilothermia • Septic arthritis - Rapid onset - Intense joint pain/swelling - Fever/chills - Inability to move the joint #Leg #pain #differential #diagnosis #lower #extremity #msk #physicalexam
