Development of post tubercular, bronchial asthma -A pilot study

Pulmonary impairment associated with obstructive airway disease is recognized as a common complication of advanced tuberculosis. Most patients suffering from tuberculosis with moderate to far advanced post treatment residual lung lesions exhibit symptoms of impaired pulmonary functions due to persistent airway obstruction but why do only a small proportion develop reversible airway obstruction to qualify for post tuberculosis bronchial asthma categorization? The present study was aimed to investigate if antitubercular drugs were involved in the pathophysiology of post-tubercular bronchial asthma. Asthmatic patients with past history of pulmonary tuberculosis who visited the hospital for treatment between Jan - Dec 2006 and 16 patients who had history of pulmonary tuberculosis and had successfully completed anti tubercular therapy but did not develop asthma were randomly chosen. During the study period there were 20 asthmatic patients with past history of antitubercular drug therapy. With 6 months of antitubercular therapy, 6 out of 20 pulmonary tuberculosis patients developed asthma (40%) and 9 out of 16 patients took 6 months of antituberculars but did not develop asthma (60%). p= 0.3, found not significant. With 8 months of antitubercular therapy, 14 out of 20 patients developed asthma (66.7%) and 7 out of 16 patients did not develop asthma (33.3%). p= 0.5, found not significant. (Fishers test). Conclusion: Anti tubercular drugs do not appear to play a role in the development of post tubercular bronchial asthma.