Calcium metabolism disorders simulating rheumatologic diseases.

Hypoparathyroidism and hyperparathyroidism may lead to spondylarthropathy or spondylarthropathy-like problems and crystal arthropathy, respectively. In this report, we present 2 cases with hypoparathyroidism and 1 case with hyperparathyroidism who developed spondylarthropathy-like disease, rheumatoid arthritis-like disease, and chondrocalcinosis, respectively. We briefly discussed relationship between calcium metabolism disorders and rheumatologic manifestations. As rheumatologists, we should be always open to other diagnosis if the treatment does not work in patients with rheumatologic diseases.