A viral etiology for our patient's acute pericarditis is suggested by the recent respiratory tract infection and no evidence for other causes. Viral infection is often assumed rather than proven, as viral cultures and serologic studies are freqently negative. As a result, many cases are classified as idiopathic. Common agents causing pericarditis are echovirus and coxsackie virus.

Other etiologies of acute pericarditis include malignancy, radiation treatment, uremia, a wide range of infectious agents, trauma and rheumatologic diseases. It may occur with an acute myocardial infarction due to local inflammation at the infarct site or several weeks post myocardial infarction due to a poorly defined immunologic reaction referred to as Dressler's syndrome. Pericarditis can also occur post cardiac surgery and with drugs such as procainamide and hydralazine.

Etiologies of pericarditis worldwide are highly variable, depending on the age of the patient, endemic diseases and the availability of health care resources. In developing countries tuberculosis and rheumatic pericarditis are common, while pericarditis from HIV infection is becoming more common.