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OR5.1 | Inflammatory Arthritis — Assignment

CLINICAL SCENARIO

This written assignment develops your ability to approach a patient presenting with polyarthritis, systematically distinguish between major inflammatory arthritides, and construct a rational management plan — core clinical competencies for a final-year MBBS student in orthopaedics.

Instructions

Read the clinical scenario provided below carefully.
Perform a structured written work-up addressing the sections in the scaffolding guide.
Apply your knowledge of rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis to the clinical reasoning.
Support your management plan with specific drug names, doses where relevant, and rationale.
Write clearly in continuous prose with appropriate sub-headings.
Word limit: 600–900 words.
Submit individually; peer review by one colleague before submission.

Clinical Scenario:
A 35-year-old male schoolteacher presents to the orthopaedic outpatient department with a 9-month history of bilateral small joint pain and swelling in the hands, morning stiffness lasting 1.5–2 hours, fatigue, and intermittent lower back pain that is worse at night and in the morning but improves with physical activity. He also reports a patch of scaly skin lesions on his elbows and scalp for 2 years. On examination: bilateral MCP and PIP joint swelling, right second and third fingers show fusiform swelling ('sausage digit'), right DIP joint is also involved. There is tenderness at the right Achilles tendon insertion. ESR 55 mm/hr, CRP 28 mg/L. RF is negative. Anti-CCP is negative.

Length: 600–900 words

What to Submit

1. Differential Diagnosis and Reasoning

Guidance: List the three most likely diagnoses and rank them by probability. For each, provide 2–3 clinical or investigation features from the scenario that support or argue against it. Specifically distinguish psoriatic arthritis from seronegative RA and from ankylosing spondylitis with peripheral joint involvement.

2. Targeted Investigations

Guidance: List the minimum investigation set required to confirm your primary diagnosis and exclude others. For each test, state what you expect to find and what that finding would mean for your diagnosis. Include relevant serological tests (RF, anti-CCP, HLA-B27), inflammatory markers, and appropriate imaging (X-ray views, MRI indications).

3. Pathophysiology of the Primary Diagnosis

Guidance: In 150–200 words, explain the underlying pathophysiology of your primary diagnosis — how the immune dysregulation leads to joint inflammation, the role of relevant cytokines or autoantibodies, and how this produces the clinical features seen (dactylitis, enthesitis, DIP involvement, or pannus formation depending on your primary diagnosis).

4. Management Plan

Guidance: Construct a phased management plan: (a) immediate symptom control — which NSAID, dose, and duration; (b) DMARD therapy — first-line choice(s) with rationale, monitoring requirements; (c) non-pharmacological measures; (d) criteria for escalation to biologic therapy. Explicitly name the DMARD(s) and state any relevant contraindications or monitoring tests.

5. Long-term Complications and Counselling

Guidance: Identify two significant long-term complications specific to your primary diagnosis and one systemic or extra-articular complication. Briefly note one counselling point for the patient regarding physical activity, disease monitoring, or work adaptations relevant to his profession as a schoolteacher.

Grading Rubric — Inflammatory Arthritis Assignment Rubric

Criterion	Points	Full-marks descriptor
Diagnostic Reasoning: Accuracy and evidence-based ranking of differential diagnoses with supporting clinical features	10 pts	Correctly identifies psoriatic arthritis as primary diagnosis with clear clinical evidence (psoriasis, dactylitis, DIP, seronegative, enthesitis); accurately distinguishes from seronegative RA and AS with peripheral involvement; reasoning is systematic and evidence-based.
Investigation Plan: Relevance, completeness, and clinical interpretation of requested tests	10 pts	Systematically requests RF, anti-CCP, HLA-B27, X-rays (hands/pelvis/spine), inflammatory markers, and explains expected findings for psoriatic arthritis (negative RF/anti-CCP, DIP erosions/pencil-in-cup on X-ray, possibly positive HLA-B27).
Pathophysiology: Accuracy and depth of mechanism explanation for the primary diagnosis	10 pts	Explains the immunological mechanism accurately — T-cell mediated synovitis, enthesitis, role of IL-17/TNF in psoriatic arthritis (or equivalent for RA — pannus/anti-CCP); links mechanism to clinical features (dactylitis = tenosynovitis; DIP involvement; enthesitis).
Management Plan: Correctness, specificity, and completeness of pharmacological and non-pharmacological management	10 pts	Names specific NSAID for symptom control; correct first-line DMARD (methotrexate for PsA peripheral disease); states monitoring requirements (LFTs, CBC for MTX); includes physiotherapy/occupational therapy; correctly states anti-TNF criteria for escalation.
Complications and Patient Counselling: Relevance and accuracy of long-term complication discussion and practical counselling	10 pts	Identifies two disease-specific complications (e.g., arthritis mutilans, uveitis, cardiovascular risk, or methotrexate toxicity) and one systemic complication; counselling is practical, patient-centred, and relevant to his occupation (e.g., joint protection, activity modification, medication monitoring schedule).

PEER REVIEW

Review your colleague's assignment using the rubric above. For each of the five criteria, provide a score and 2–3 sentences of constructive feedback explaining your reasoning. Pay particular attention to: (1) whether the clinical diagnosis is correctly justified using specific features from the case scenario; (2) whether the DMARD treatment plan names specific drugs with monitoring requirements; (3) whether the pathophysiology accurately links mechanism to the clinical features in the scenario. Submit your peer review within 3 days of receiving the assignment.