ULT No Role CPPD — SCE Rheumatology MCQ

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EasyCrystal ArthropathyULT No Role CPPDSCE Rheumatology

A 60-year-old man presents with acute monoarthritis. Synovial-fluid microscopy demonstrates rhomboid-shaped, positively birefringent calcium pyrophosphate crystals; culture is negative and no monosodium urate crystals are seen. He has no history of gout or other indication for urate-lowering therapy. Once the acute episode has been treated, which long-term crystal-lowering approach is appropriate?

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Correct answer: D — Do not initiate urate-lowering therapy

The correct answer is D. This is confirmed acute calcium pyrophosphate crystal arthritis, not gout. Urate-lowering therapies alter urate production or disposal and reduce monosodium urate deposition; they neither remove calcium pyrophosphate crystals nor prevent CPPD by lowering serum urate. No currently available treatment reliably dissolves CPP crystals. Acute CPP crystal arthritis is treated with anti-inflammatory measures selected according to comorbidity, such as aspiration with intra-articular corticosteroid, an NSAID, colchicine or a short systemic corticosteroid course. Allopurinol and febuxostat inhibit uric-acid production, probenecid is uricosuric, and pegloticase enzymatically degrades urate; therefore, none is indicated for isolated CPPD. Urate-lowering therapy would only be appropriate if the patient independently met criteria for treatment of coexisting gout or another urate-related disorder.

Reference: Pascart T, Filippou G, Lioté F, et al. Calcium pyrophosphate deposition disease. Lancet Rheumatology. 2024;6(11):e791-e804. https://pubmed.ncbi.nlm.nih.gov/21257614/