Scenario: A 52-year-old man presents to the Emergency Department at 3 AM with sudden onset of severe pain, swelling, and redness in his right big toe. He rates the pain as 9/10 and says he cannot bear any weight on the foot. The pain woke him from sleep about 4 hours ago.
Your task: Take a comprehensive history from this patient.
| 1. Introduction & Rapport 3 marks | |
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| 2. History of Presenting Complaint 14 marks | |
| A. Pain Characteristics (SOCRATES) 5 marks | |
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| B. Associated Local Symptoms 3 marks | |
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| C. Triggers & Precipitating Factors 3 marks | |
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| D. Systemic & Red Flag Symptoms 3 marks | |
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| 3. Past Medical History 4 marks | |
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| 4. Drug History & Allergies 3 marks | |
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| 5. Family History 2 marks | |
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| 6. Social History & Lifestyle 2 marks | |
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Information from History: 52-year-old man with sudden onset severe pain in right first MTP joint that woke him from sleep. Reports swelling, redness, and inability to bear weight. Had a celebratory dinner with steak and wine yesterday. Has history of hypertension on thiazide diuretic. No fever reported.
Your task: Perform a focused and systematic musculoskeletal examination of the affected joint and relevant systems.
| 1. Initial Approach & General Inspection 6 marks | |
| A. Professional Approach 2 marks | |
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| B. General Assessment 2 marks | |
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| C. Hands and Skin Inspection 2 marks | |
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| 2. Affected Joint Examination (1st MTP) 10 marks | |
| A. Inspection (Look) 4 marks | |
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| B. Palpation (Feel) 4 marks | |
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| C. Movement (Move) 2 marks | |
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| 3. Other Joint Screening 6 marks | |
| A. Lower Limb Joint Screen 3 marks | |
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| B. Upper Limb & Bursa Screen 3 marks | |
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| 4. Relevant Systemic Examination 4 marks | |
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Test your understanding of the key clinical features, pathophysiology, and examination findings in acute monoarthritis and crystal arthropathies. Click each question to reveal the answer.
Clinical Summary: 52-year-old man with sudden onset severe pain, swelling, and erythema of the right first MTP joint that woke him from sleep. History of hypertension on thiazide diuretic. Had steak and wine dinner yesterday. Examination reveals exquisitely tender, swollen, erythematous first MTP joint with overlying shiny skin. Afebrile. No other joints involved.
Your task: Present your differential diagnoses in order of likelihood, justifying your clinical reasoning for each.
| 1. Top Differential Diagnoses 8 marks | |
| A. Most Likely Diagnosis 4 marks | |
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| B. Second Most Likely Diagnosis 2 marks | |
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| C. Third Differential Diagnosis 2 marks | |
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| 2. Alternative Diagnoses to Consider 6 marks | |
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| 3. Red Flags & Must-Not-Miss Diagnoses 6 marks | |
| A. Septic Arthritis Warning Signs 3 marks | |
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| B. Other Serious Considerations 3 marks | |
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Working Diagnosis: Acute gout (crystal arthropathy) affecting the right first MTP joint, with septic arthritis as an important differential to exclude.
Your task: Outline the investigations you would request, explaining the rationale for each and what findings you would expect.
| 1. Gold Standard: Joint Aspiration 6 marks | |
| A. Synovial Fluid Analysis 4 marks | |
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| B. Expected Fluid Characteristics 2 marks | |
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| 2. Laboratory Investigations 6 marks | |
| A. Essential Blood Tests 4 marks | |
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| B. Metabolic and Comorbidity Screen 2 marks | |
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| 3. Imaging Studies 4 marks | |
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| 4. Additional Investigations 2 marks | |
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Test your understanding of the investigations used in diagnosing and managing crystal arthropathies. Click each question to reveal the answer.
Confirmed Diagnosis: Acute gout affecting the right first MTP joint, confirmed by joint aspiration showing negatively birefringent needle-shaped monosodium urate crystals. Gram stain negative. Patient has hypertension (on thiazide), eGFR 65 mL/min, and no history of peptic ulcer disease.
Your task: Present a comprehensive management plan for this patient, including acute treatment, long-term management, and patient education.
| 1. Acute Flare Management 8 marks | |
| A. First-Line Pharmacotherapy 4 marks | |
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| B. Supportive & Non-Pharmacological 4 marks | |
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| 2. Urate-Lowering Therapy (ULT) 6 marks | |
| A. ULT Indications & Initiation 3 marks | |
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| B. ULT Drug Selection 3 marks | |
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| 3. Lifestyle Modification & Comorbidities 5 marks | |
| A. Dietary Modifications 3 marks | |
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| B. Comorbidity & Medication Review 2 marks | |
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| 4. Patient Education & Follow-Up 3 marks | |
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Test your understanding of gout management principles, drug mechanisms, and special situations. Click each question to reveal the answer.
| Feature | Gout | Pseudogout | Septic Arthritis |
|---|---|---|---|
| Typical Joint | 1st MTP (podagra) | Knee, wrist | Knee, hip |
| Age Group | 40-60 years, male | >65 years | Any age |
| Onset | Sudden (hours) | Acute to subacute | Rapid (hours-days) |
| Fever | Usually absent | Low-grade possible | Usually present |
| Crystals | MSU (negative, needle) | CPPD (positive, rhomboid) | None |
| Synovial WBC | 10,000-50,000/μL | 10,000-50,000/μL | >50,000/μL |
| Red Flag | What It Suggests / Action Required |
|---|---|
| Fever with hot joint | Septic arthritis until proven otherwise - urgent joint aspiration, Gram stain, culture; consider IV antibiotics |
| Immunocompromised patient | Higher risk of septic arthritis; lower threshold for aspiration; atypical organisms possible |
| Prosthetic joint involvement | Prosthetic joint infection is emergency - urgent orthopedic referral; may need surgical washout |
| Overlying skin break/wound | Portal of entry for infection - increases septic arthritis risk; examine carefully for cellulitis |
| Failure to respond to treatment | Reconsider diagnosis - may be septic arthritis, CPPD, or dual pathology; repeat aspiration |
| Multiple joints + systemic symptoms | Consider disseminated gonococcal infection, reactive arthritis, rheumatoid arthritis, viral arthritis |
| Recent joint procedure/injection | Iatrogenic septic arthritis risk - aspiration and culture mandatory |
| IV drug use | High risk for septic arthritis (including atypical joints like sternoclavicular); blood cultures essential |
| High Probability for Gout | Lower Probability / Consider Alternatives |
|---|---|
| Male patient aged 40-60 | Premenopausal woman (rare in this group) |
| First MTP joint involvement (podagra) | Large joint as first presentation (consider CPPD) |
| Sudden onset, nocturnal, peak <24h | Gradual onset over days-weeks |
| Clear dietary/alcohol trigger | Recent GI/GU infection (reactive arthritis) |
| History of similar self-limiting episodes | First episode with fever (exclude septic) |
| On thiazide diuretic or low-dose aspirin | Rash, nail changes (psoriatic arthritis) |
| Condition | Key Clinical Features | Examination Findings | Investigations | Key Differentiators |
|---|---|---|---|---|
| Acute Gout | Sudden onset, nocturnal, excruciating pain, 1st MTP most common, dietary/alcohol trigger, male predominance | Exquisite tenderness, erythema extending beyond joint, warmth, swelling, tophi (chronic), afebrile usually | Negatively birefringent needle-shaped crystals, elevated WBC in fluid, serum urate may be normal | Podagra, clear trigger, rapid response to NSAIDs/colchicine, self-limiting |
| Septic Arthritis | Fever, rigors, rapid onset, single hot joint, risk factors (DM, immunosuppression, IVDU, prosthesis) | Fever, toxic appearance, severely restricted ROM, joint held in flexion, overlying cellulitis possible | Synovial WBC >50,000/μL, positive Gram stain (50-75%), positive culture, elevated CRP/WCC | Fever + hot joint, systemic toxicity, risk factors, orthopedic emergency |
| Pseudogout (CPPD) | Elderly patient (>65), knee/wrist most common, acute or chronic, associated with OA, metabolic conditions | Similar to gout but larger joints, may have OA changes, less dramatic erythema, low-grade fever possible | Positively birefringent rhomboid crystals (weak), chondrocalcinosis on X-ray | Older age, large joints, X-ray chondrocalcinosis, crystal morphology |
| Reactive Arthritis | Preceding infection (1-4 weeks prior) - urethritis, diarrhea; young adults, asymmetric oligoarthritis | Large joint involvement, enthesitis (Achilles), dactylitis, conjunctivitis, keratoderma, circinate balanitis | Sterile joint fluid, HLA-B27 positive (50-80%), stool/urethral cultures, elevated inflammatory markers | Preceding GI/GU infection, extra-articular features, young patient |
| Psoriatic Arthritis | Psoriasis history (may be subtle - scalp, nails, natal cleft), DIP involvement, dactylitis, asymmetric | Nail pitting/onycholysis, skin plaques, "sausage digits" (dactylitis), enthesitis, DIP swelling | RF negative, pencil-in-cup deformity on X-ray, periostitis, negative crystals | Skin/nail changes, DIP involvement, dactylitis, family history |
| Cellulitis | Spreading erythema, skin warmth, may have portal of entry (wound, tinea pedis), fever common | Ill-defined erythema spreading beyond joint, skin tenderness, lymphangitis, regional lymphadenopathy | Elevated WCC/CRP, blood cultures if systemic, joint aspiration normal if no septic arthritis | Spreading skin infection, not joint-centered, portal of entry, lymphangitis |
| OA Flare | Known OA, gradual worsening, mechanical pain pattern, older patient, weight-bearing joints | Bony swelling, crepitus, mild warmth, Heberden's/Bouchard's nodes, reduced ROM | Non-inflammatory fluid (<2000 WBC), joint space narrowing, osteophytes, subchondral sclerosis on X-ray | Mechanical symptoms, less acute, bony changes, older patient |
| Rheumatoid Arthritis | Symmetrical polyarthritis, small joints (MCP, PIP, wrists), morning stiffness >1 hour, gradual onset | Symmetrical swelling, MCP/PIP/wrist involvement, boggy synovitis, later deformities (swan neck, boutonniere) | RF positive (70%), Anti-CCP positive (more specific), elevated ESR/CRP, erosions on X-ray | Symmetrical, polyarticular, morning stiffness, RF/Anti-CCP positive |
| Phase | Treatment Options | Key Considerations |
|---|---|---|
| Acute Flare | NSAIDs, Colchicine, Corticosteroids | Start within 24h; consider renal function, GI history, diabetes |
| Prophylaxis | Low-dose colchicine or NSAID | When starting ULT; continue 3-6 months |
| Urate-Lowering | Allopurinol (1st line), Febuxostat | Start low, titrate to target <360 μmol/L |
| Lifestyle | Diet, alcohol, weight, hydration | Adjunct to pharmacotherapy; modest effect alone |
Format: 52-year-old man with acute toe pain - take a focused history
Key focus: SOCRATES for pain, triggers (alcohol, diet, medications), risk factors, previous episodes, comorbidities (CKD, HTN, CVD), red flags for septic arthritis
Format: Examine this patient's foot/perform a musculoskeletal examination
Key focus: Systematic Look-Feel-Move of affected joint, compare sides, check for tophi (ears, elbows, Achilles), screen other joints, assess for chronic changes
Format: Explain the diagnosis of gout and management plan to the patient
Key focus: Explain what gout is (crystal deposition), acute treatment options, lifestyle modifications (alcohol, diet), long-term ULT rationale, flare action plan, importance of adherence
Format: Interpret synovial fluid results, X-ray findings, or discuss investigation results
Key focus: Crystal identification (MSU vs CPPD), synovial fluid analysis (WBC count, Gram stain), X-ray features (punched-out erosions vs chondrocalcinosis), serum urate interpretation
Format: Patient with acute gout - outline immediate management
Key focus: Analgesia choice (NSAID vs colchicine vs steroid), dosing, contraindications assessment (renal function, GI history), supportive measures (rest, ice, elevation), safety-netting
Format: NOT a straightforward first presentation of podagra
| Atypical Presentation | Clinical Implication |
|---|---|
| Polyarticular gout | More common in chronic/tophaceous gout; wider differential (RA, viral); may need multiple joint aspirations |
| Gout in young woman | Rare - consider secondary causes (CKD, myeloproliferative, inherited enzyme defects); investigate thoroughly |
| Gout with fever | Must exclude septic arthritis - joint aspiration mandatory; can have dual pathology |
| Gout in CKD patient | Treatment modifications needed - avoid/reduce NSAIDs, adjust colchicine dose, careful ULT titration |
| Post-operative gout flare | Common trigger; must differentiate from wound infection or septic arthritis; steroids often safest option |
| Gout with prosthetic joint nearby | Low threshold for aspiration of prosthetic joint if any concern; orthopedic involvement early |
| Tophaceous gout | Indicates chronic undertreated disease; aggressive ULT needed (target urate <300 μmol/L); may need surgical debulking |
| Allopurinol hypersensitivity | DRESS/SJS/TEN - stop immediately; supportive care; febuxostat may be cautiously trialed later (some cross-reactivity) |
| Clinical Scenario | Management Decision |
|---|---|
| Classic podagra, afebrile, known gout, clear trigger | Clinical diagnosis acceptable; start NSAIDs/colchicine; aspiration optional |
| First presentation, typical features, no red flags | Aspiration recommended to confirm diagnosis; start treatment empirically while awaiting results |
| Hot swollen joint with fever | Urgent joint aspiration - septic arthritis until proven otherwise; consider empirical antibiotics |
| Gout in patient with eGFR 25 | Avoid NSAIDs; low-dose colchicine (0.5mg daily/every other day) or prednisolone; careful ULT dosing |
| Gout in patient with active peptic ulcer | Avoid NSAIDs; colchicine or prednisolone preferred; intra-articular steroid excellent option |
| Patient on warfarin with acute gout | Colchicine safest (but check interactions); prednisolone; avoid NSAIDs (INR interaction + bleeding risk) |
| Recurrent attacks despite allopurinol 300mg | Check compliance and serum urate; titrate allopurinol upward (can go to 800-900mg); ensure target achieved |
| Patient develops rash on allopurinol | Stop immediately; mild rash - may rechallenge cautiously; severe/systemic - never rechallenge, use febuxostat |
| Starting ULT - how to prevent flares | Start low dose, titrate slowly; prophylactic colchicine 0.5mg daily or low-dose NSAID for 3-6 months |
| Patient asks about diet alone for gout control | Diet helps but modest effect (10-15% urate reduction); pharmacotherapy usually needed; diet is adjunct |