Tuberculous pericarditis developing during chemotherapy.

A 6-year-old boy with active tuberculosis developed a pericarditis 9 weeks after starting adequate chemotherapy. Although no Mycobacterium tuberculosis was isolated from the pericardial fluid we assume, for several reasons, that the pericarditis was caused by tuberculosis. Consequently, it is important to be aware of possible serious complications even during treatment with adequate antituberculous drugs.