A ‘crowning’ diagnosis: Fever, neck pain, and diffuse polyarthritis as a fulminant first presentation of pseudogout
Background: Calcium Pyrophosphate Deposition Disease (CPPD) rarely presents as a diffuse polyarthritis with systemic features. Case presentation: A 75-year-old man with no prior history of rheumatic disease presented with acuteonset diffuse polyarthritis and severe neck pain, accompanied by fevers, leucocytosis, and elevated acute phase reactants. After excluding infectious aetiologies, a synovial fluid aspirate revealed a highly neutrophilic inflammatory infiltrate and rare calcium pyrophosphate dihydrate crystals. Cervical CT confirmed periodontoid calcium deposits consistent with the crowned dens syndrome. The patient was diagnosed with acute CPPD, and his joint and neck pain improved rapidly with colchicine and glucocorticoids. Conclusion: In addition to arthrocentesis and microscopic crystal analysis, cervical CT can lend support to a diagnosis of pseudogout complicated by CDS. In patients presenting with fever and neck pain, recognition that CDS can be a prominent or isolated feature of acute CPPD facilitates diagnosis, limits unnecessary procedures, and allows for early initiation of appropriate therapy.