Paradoxical reaction during treatment of tuberculous brain abscess in a patient with AIDS.

A paradoxical worsening of pre-existing lesion or an apparition of new lesions in patients with tuberculosis during appropriate antituberculous therapy has been reported since the early years of modern chemotherapy. Such exacerbations have been noted most commonly with lung involvement, pleural effusion, lymphadenitis, and intracranial tuberculomas. In acquired immunodeficiency syndrome (AIDS)-era, paradoxical reactions are related more frequently to concurrent administration of highly active antiretroviral therapy (HAART) with antituberculous therapy. In these patients, the time from initiation of HAART to the presentation of immune reconstitution inflammatory syndrome is very variable, occurring as few as 10 days to as long as 180 days.