Abstract

Calcium pyrophosphate deposition (CPPD) disease is arthritis caused by calcium pyrophosphate (CPP) crystals. Patients typically present with the acute onset of monoarticular or polyarticular arthritis. The polyarticular form can simulate systemic disease as rheumatoid arthritis, polymyalgia rheumatica or gout. We present the case of a 77-year-old man with a 6-week history of a full spectrum of signs and symptoms compatible with RS3PE. He was treated by prednisolone 15 mg/day. Because persisting swelling and pain, he was admitted for further investigations. Radiographs of the knees revealed significant chondrocalcinosis. Analysis of synovial fluid revealed presence of calcium pyrophosphate crystals. This case demonstrated the importance of considering the possibility of crystal-induced arthritis such as CPPD, as well as a malignant disease when diagnosing the primary disease responsible for RS3PE syndrome. Conservative therapy with steroids rapidly resolved all symptoms.