ACUTE BENIGN PERICARDITIS OF UNKNOWN ORIGIN

Since the earliest description of " idiopathic pericarditis " by Hodges in 1854 (Carmichael et al., 1951) occasional records of small series or single cases of a benign form of pericarditis have been reported. Comer (1927) reported a case of pericarditis that he thought to be a sequel of acute sinusitis. Bing (1933) described six examples of a mild form of pericarditis, sometimes associated with pleurisy, clearly distinguishable from rheumatic and tuberculous pericarditis; he believed the disease to be infectious and suggested the title " epidemic pericarditis." The condition attracted little notice until Barnes and Burchell (1942) described its features in more precise detail and established it as a clinical entity. Since then it has been more widely recognized, especially in the United States. Nay and Boyer (1946) found 15 examples of " idiopathic pericarditis " among 46 cases of pericarditis of varied etiology admitted to an Army Rheumatic Centre. Logue and Wendkos (1948) were of the opinion that the condition was often overlooked and in reviewing 77 cases of pericarditis they found 17 examples of this benign form, 6 of which had been originally diagnosed as cardiac infarction. Feder et al. (1950) described 5 cases; they believed the diagnosis was usually missed entirely and that the symptoms, when mild, were usually mistaken for influenza or pleurisy, and when severe, for coronary occlusion. Levy and Patterson (1950), after a study of 27 cases, thought the clinical picture was quite distinctive, the chief differential diagnosis being from cardiac infarction. Carmichael et al. (1951) in a full review of 50 cases, found that they had encountered the condition more frequently in recent years. To date, little attention has been paid to the condition in this country. The following 5 cases illustrate many of the typical features of the condition and show some of the difficulties that may arise in differential diagnosis.