Paradoxical pericarditis in an immunocompetent patient with mediastinal tuberculous lymphadenitis and endobronchial TB: A case report.

Background: Paradoxical reaction (PR) refers to a worsening of existing or new TB-related lesions after initiating effective anti-tuberculosis therapy. While commonly observed in lymph node or CNS TB, PR involving the pericardium is exceedingly rare in immunocompetent patients. Case presentation: A 22-year-old Vietnamese man with mediastinal tuberculous lymphadenitis and endobronchial TB was started on standard anti-TB therapy. After initial improvement, he developed pericardial effusion three months into treatment. Cultures and PCR were negative, but elevated ADA levels were detected. Based on clinical course and exclusion of treatment failure or coinfection, paradoxical pericarditis was diagnosed. Corticosteroids and levofloxacin were added empirically, with resolution of symptoms. Conclusion: This case highlights a rare extrapulmonary manifestation of PR, reinforcing the need to distinguish it from treatment failure or TB progression in immunocompetent hosts.