Pseudogout is an important causative disease of febrile illness in elderly patients. We experienced cases of pseudogout during or after the progression of inflammatory disease.
We investigated 14 patients with pseudogout admitted to the Department of Geriatric Medicine at Kyorin University Hospital. Seven patients who developed inflammatory disease prior to the onset of pseudogout are described in greater detail.
The affected joint was the knee joint in 12 of 14 cases. Other joints were affected in four cases, and four patients had more than two affected joints in this series. Clear joint cartilage calcification was noted on X-rays in nine of 14 cases, and CPPD crystals were detected in two patients treated with joint puncture. NSAIDs were administered in all cases for treatment. Seven patients had a preceding inflammatory disease, with infectious disease in all cases. Repeat elevation of temperature and inflammatory reactions were seen in seven cases, with progression to bimodal disease in two cases. The average duration of antimicrobial use was 11 days. In three cases, the average duration of antimicrobial use was 33 days, and two or more antimicrobials were used for long-term treatment.
Pseudogout appears as delayed infective disease and fever of unknown origin in the elderly. This condition may easily be overlooked until joint symptoms become apparent. It is extremely important to keep pseudogout in mind as a differential diagnosis of thermogenesis in elderly patients.