What are the causes of pericarditis in patients of different age groups and demographics?

Causes of Pericarditis

Primary Etiologic Framework

The causes of pericarditis vary dramatically by geographic location and patient demographics: viral infections predominate in developed countries (North America and Western Europe), while tuberculosis is the leading cause worldwide, particularly in developing nations and HIV-endemic regions. 1, 2, 3

Infectious Causes

Viral Pericarditis

• Viral infection is the most common cause in developed countries, accounting for the majority of idiopathic cases (42-49% in tertiary referral centers). 1
• Common viral pathogens include enteroviruses (Coxsackie A and B), echoviruses, adenoviruses, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, influenza, parvovirus B19, hepatitis C virus, and HIV. 1, 4
• Enteroviral pericarditis follows seasonal epidemics of Coxsackie and Echovirus infections. 1
• Cytomegalovirus pericarditis has increased incidence in immunocompromised and HIV-infected patients. 1

Bacterial Pericarditis

• Tuberculosis is the most common cause of pericarditis globally, responsible for >90% of cases in HIV-infected individuals and 50-70% in non-HIV-infected individuals in TB-endemic developing countries. 1, 2, 4
• In developed countries, TB accounts for only ≤4% of pericardial disease but remains critical among immigrants from underdeveloped nations and HIV-infected patients. 1
• Purulent bacterial pericarditis (S. aureus, K. pneumoniae, M. avium) is relatively uncommon in developed countries but carries high mortality (17-40% at 6 months) and high risk of progression to constriction (20-30%). 1

Other Infectious Causes

• Fungal pericarditis occurs particularly in immunocompromised patients. 4

Non-Infectious Causes

Post-Cardiac Injury Syndromes

• Post-cardiac surgery pericarditis accounts for 11-37% of cases in developed countries. 1, 3
• Post-myocardial infarction syndrome (Dressler syndrome) has autoimmune pathogenesis. 2, 4
• Post-pericardiotomy syndrome occurs after cardiac procedures. 2, 3

Autoimmune and Inflammatory Disorders

• Systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis, scleroderma, systemic vasculitides, and sarcoidosis are associated with pericarditis, accounting for 5-15% of cases. 2, 4
• Familial Mediterranean fever and other autoinflammatory conditions cause pericarditis. 2
• Drug-induced lupus-like syndrome from procainamide and hydralazine can cause pericarditis. 2, 5

Neoplastic Causes

• Malignancy accounts for 10-25% of pericardial effusions in developed countries. 4
• Secondary metastatic tumors are 40 times more common than primary pericardial tumors, with lung cancer, breast cancer, lymphomas, malignant melanoma, and leukemias being the most frequent. 2, 4
• Primary pericardial mesothelioma is rare. 2

Metabolic and Endocrine Disorders

• Uremia and dialysis-related pericarditis are major metabolic causes. 2, 4
• Hypothyroidism (myxedema) causes pericardial effusion in 5-30% of hypothyroid patients, though tamponade is rare. 2, 4
• Anorexia nervosa is associated with pericarditis. 2

Radiation-Induced Pericarditis

• Post-radiation therapy accounts for 9-31% of cases, mostly after treatment for Hodgkin's disease or breast cancer. 1

Traumatic and Iatrogenic Causes

• Direct injury from penetrating thoracic trauma or esophageal perforation. 2, 4
• Indirect injury from non-penetrating thoracic trauma. 2, 4
• Antineoplastic drugs such as doxorubicin can cause pericarditis. 2

Cardiovascular Causes

• Chronic heart failure causes transudative pericardial effusion due to increased systemic venous pressure. 2, 4
• Pulmonary arterial hypertension causes effusion in 25-30% of cases, typically small and rarely causing hemodynamic compromise. 4

Demographic Considerations

• Men aged 16-65 years have higher risk for pericarditis compared to women, with the highest risk difference among young adults. 2
• The median age for myocarditis and pericarditis is 30-45 years, affecting men more than women. 6

Critical Clinical Pitfalls

• Risk of progression to constrictive pericarditis varies dramatically by etiology: <1% for viral/idiopathic, 2-5% for immune-mediated and neoplastic, and 20-30% for bacterial (especially purulent) pericarditis. 1
• In patients with cardiac tamponade without inflammatory signs, suspect neoplastic etiology (likelihood ratio 2.9). 4
• Severe effusion without tamponade and without inflammatory signs typically indicates chronic idiopathic etiology (likelihood ratio 20). 4