Pyrophosphate arthropathy has a wide spectrum of clinical symptoms and is a common cause of synovitis in the elderly. The acute "pseudogout" attack is the most commonly recognized, but chronic synovitis might be just as prevalent. Familial pyrophosphate arthropathy with a dominant autosomal heredity is a rare form, with an earlier debut and a more severe prognosis. Another rare expression of pyrophosphate arthropathy is severe joint destruction. The cause of pyrophosphate arthropathy is still unknown. Both individual reactivity and crystal properties determine the intensity of the inflammatory response to crystals.