Tocilizumab masking infection — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

HardRheumatological PharmacologyTocilizumab masking infectionSCE Rheumatology

A woman with longstanding SLE has reducible ulnar deviation, swan-neck deformities and MCP subluxation. Radiographs show no marginal erosions despite marked deformity. What is the diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Jaccoud non-erosive deforming hand arthropathy

Explanation lettering: B = shown as A · D = shown as B · A = shown as C · C = shown as D

E is correct. Jaccoud arthropathy produces deforming but classically reducible non-erosive arthropathy through capsular and tendon laxity, most often in SLE. Rheumatoid arthritis would usually produce fixed deformity with marginal erosions in a longstanding severe phenotype. Multicentric reticulohistiocytosis is destructive and papulonodular. Arthritis mutilans causes erosive osteolysis. CPPD may mimic inflammatory arthritis but does not explain this reducible non-erosive pattern. Ultrasound or MRI can show soft-tissue inflammation, but the radiographic absence of erosions remains the key discriminator.

Reference: 2026 BSR guideline for systemic lupus erythematosus across the life course: https://academic.oup.com/rheumatology/article/65/6/keag223/8713811