Subacromial/subdeltoid bursa abscesses. An overlooked diagnosis.

Four subacromial/subdeltoid bursa abscesses were treated in four patients with systemic illnesses. The symptoms and signs of abscesses were minimal in all four patients. In three patients who were chronically ill and debilitated, diagnosis was established only after subacromial space abscesses were encountered during incision and drainage of the glenohumeral or acromioclavicular joint. In these three patients, the subacromial bursa abscesses coexisted with clinically diagnosed mild or resolving shoulder pyarthrosis. All had intact rotator cuffs. The subacromial/subdeltoid space should be evaluated in all cases of suspected glenohumeral pyarthrosis. Computed tomography or magnetic resonance imaging may help detect abscesses and indicate surgical therapy.