The sacroiliitis of acute Reiter's syndrome.

Sacroiliitis can be demonstrated radiologically in over one-third of patients with chronic Reiter's syndrome. We have used a bone scan technique with digital analysis which will quantitatively assess the sacroiliac joints, and have found abnormalities in 24 of 33 patients with active Reiter's syndrome. It seems likely therefore that sacroiliitis is a common feature in patients with early Reiter's syndrome and while in most patients it resolves with resolution of disease activity, in some it may persist with the development of overt radiological changes.