Idiopathic (nonspecific, probably viral)
Infectious causes
Viruses: coxsackievirus A and B, hepatitis viruses, human immunodeficiency virus, influenza, measles virus, mumps virus, varicella virus
Bacteria: gram-positive and gram-negative organisms; rarely, Mycobacterium tuberculosis
Fungi (most common in immunocompromised patients): Blastomyces dermatitidis, Candida species, Histoplasma capsulatum
Echinococcus granulosus
Noninfectious causes
Acute myocardial infarction*
Aortic dissection
Renal failure
Malignancy: breast cancer, lung cancer, Hodgkin's disease, leukemia, lymphoma by local invasion
Radiation therapy (usually for breast or lung cancer)
Chest trauma
Postpericardiotomy
Cardiac procedures: catheterization, pacemaker placement, ablation
Autoimmune disorders: mixed connective tissue disorder, hypothyroidism, inflammatory bowel disease, rheumatoid arthritis, scleroderma, spondyloarthropathies, systemic lupus erythematosus, Wegener's granulomatosis
Sarcoidosis
Medications
Dantrolene (Dantrium), doxorubicin (Adriamycin), hydralazine (Apresoline; brand not available in the United States), isoniazid (INH), mesalamine (Rowasa), methysergide (Sansert; brand not available in United States), penicillin, phenytoin (Dilantin), procainamide (Procanbid), rifampin (Rifadin)