What is the workup for sudden severe pain in the left great toe?

Workup for Sudden Severe Pain in the Left Great Toe

The most critical first step is to obtain a detailed history focusing on trauma, systemic symptoms (fever, chills), and risk factors for gout or infection, followed by immediate physical examination to assess for signs of infection, fracture, or acute inflammatory arthritis, with urgent laboratory testing (serum uric acid, CBC, CRP) and plain radiographs as the initial imaging modality. 1, 2

Immediate Clinical Assessment

History - Key Elements to Elicit

• Onset and mechanism: Determine if there was trauma (hyperextension injury suggesting turf toe, crush injury suggesting fracture) versus atraumatic onset (suggesting gout, infection, or inflammatory arthritis) 3, 4, 5
• Systemic symptoms: Fever, chills, or constitutional symptoms raise concern for infection or systemic inflammatory process 6
• Risk factors for specific diagnoses:
  • Gout: History of prior attacks, alcohol use, purine-rich diet, diuretic use 7
  • Infection: Diabetes, immunosuppression, recent trauma or puncture wound 6
  • Fracture: Recent increased activity, change in walking surface, or direct trauma 1, 2, 3
• Quality of pain: Burning or tingling suggests neurologic causes requiring subspecialist referral 1, 2

Physical Examination - Critical Findings

• Inspection: Look for erythema, swelling, warmth, open wounds, or deformity 6, 4
• Palpation: Assess for point tenderness over specific structures:
  • First metatarsophalangeal (MTP) joint (gout, turf toe, hallux rigidus) 4, 5
  • Sesamoid bones (sesamoiditis, fracture) 3, 4
  • Entire great toe phalanges (fracture) 3
• Range of motion: Pain with passive dorsiflexion suggests turf toe or hallux rigidus 4, 5
• Vascular assessment: Palpate dorsalis pedis and posterior tibial pulses, especially in diabetic patients 6
• Neurologic examination: Test sensation with monofilament if diabetic 6
• Signs of severe infection: Look for systemic inflammatory response, rapid progression, crepitus, extensive necrosis, or bullae - these require urgent surgical consultation 6

Laboratory Testing

Initial Blood Work

• Complete blood count (CBC): Elevated white blood cell count suggests infection or inflammatory process 6
• C-reactive protein (CRP): Markedly elevated (>100 mg/L) suggests infection or severe inflammation 6
• Serum uric acid: Elevated level supports gout diagnosis, though normal levels do not exclude acute gout 7
• Blood glucose: If diabetic or at risk, as hyperglycemia complicates infection 6
• Blood cultures: If fever or systemic signs of infection present 6

Synovial Fluid Analysis (If Joint Effusion Present)

• Arthrocentesis of first MTP joint: Essential for definitive diagnosis of gout (monosodium urate crystals) or septic arthritis (positive Gram stain/culture, elevated white blood cell count >50,000/μL) 7

Imaging Studies

Initial Imaging - Plain Radiographs

• Weight-bearing radiographs of the foot (if patient can tolerate): Initial imaging modality for all patients with great toe pain 1, 2
• Look for:
  • Fractures of phalanges or sesamoids 3, 4
  • Joint space narrowing or osteophytes (hallux rigidus) 4
  • Soft tissue swelling or gas in tissues (infection) 6
  • Erosions or tophi (chronic gout) 7

Critical pitfall: Initial radiographs have poor sensitivity (12-56%) for stress fractures, so negative X-rays do not exclude fracture 8

Advanced Imaging - When Initial Radiographs Are Negative

• If pain persists >1 week with negative radiographs: MRI without contrast or CT without contrast are equivalent alternatives for detecting occult fractures, osteomyelitis, or soft tissue pathology 1, 2, 8
• MRI is preferred for:
  • Suspected osteomyelitis (bone marrow edema pattern) 6
  • Turf toe with suspected plantar plate injury 5
  • Sesamoid avascular necrosis 3, 4

Differential Diagnosis Algorithm

If Atraumatic Sudden Onset with Severe Pain

1. First consideration - Acute gout: Exquisitely tender, erythematous, warm first MTP joint ("podagra")

   • Confirm with synovial fluid analysis showing negatively birefringent monosodium urate crystals 7
   • Treat with low-dose colchicine (1.2 mg, then 0.6 mg one hour later for total 1.8 mg) within 12 hours of symptom onset 7

2. Second consideration - Septic arthritis: Fever, systemic symptoms, diabetes or immunosuppression

   • Requires urgent arthrocentesis, blood cultures, and empiric antibiotics 6
   • Surgical consultation if no improvement within 24 hours 6

If Traumatic Onset

1. Hyperextension mechanism - Turf toe: Pain with passive dorsiflexion, tenderness over plantar MTP joint

   • Grade I-II: Conservative management with rest, ice, taping 5
   • Grade III: MRI to assess plantar plate integrity, may require surgery 5

2. Direct trauma or crush injury - Fracture: Point tenderness over phalanx or sesamoid

   • If radiographs negative but high suspicion: MRI or CT at 1 week 1, 2, 8

If Diabetic Patient

Heightened concern for infection: Even without fever or leukocytosis, diabetic foot infections can be limb-threatening 6

• Probe any wound to assess depth and bone involvement 6
• Obtain wound cultures from debrided tissue, not swabs 6
• Admit for IV antibiotics if moderate-to-severe infection (systemic signs, extensive erythema >2 cm, deep tissue involvement) 6
• Urgent surgical consultation if gas in tissues, abscess, necrotizing infection, or critical ischemia 6

Common Pitfalls to Avoid

• Do not dismiss infection in diabetics without fever: Absence of fever or leukocytosis should not dissuade consideration of surgical exploration 6
• Do not rely solely on initial radiographs: Stress fractures and early osteomyelitis may not be visible initially 1, 2, 8
• Reexamine at 3-5 days if initial exam limited by swelling: Excessive edema within 48 hours can obscure findings 1
• Avoid corticosteroid injections near tendons: Risk of tendon rupture, particularly Achilles and extensor tendons 1, 8