Interstitial
pulmonary fibrosis in developing countries is now diagnosed with an increased frequency. Increased awareness and more frequent availability of computed tomography and fiberoptic bronchoendoscopy have helped in making the diagnosis more often. The spectrum of diseases causing
pulmonary fibrosis is broadly similar to that seen in the West. Connective tissue disorders such as
systemic sclerosis and
rheumatoid arthritis and
sarcoidosis are more common causes. Idiopathic
fibrosis is seen in approximately half the patients.
Pneumoconiosis such as
silicosis are also important. Diagnosis is often established on the basis of clinical features and radiologic findings alone. Transbronchial lung biopsy is used as a frequent method to make histologic diagnosis. Some of the causes described from India are rather rare. One of the interesting examples included a patient in whom
pulmonary fibrosis was related to his ascent to very high altitude. Extreme cold, solar radiation, and other factors complicating low atmospheric
oxygen pressure were implicated as causative factors. Lung
fibrosis, secondary to exposure to toxic gas (
methyl isocyanate), is reported in survivors of the Bhopal gas leakage tragedy of 1984. Serial bronchoalveolar studies have show elevated
fibronectin levels and the presence of macrophage-neutrophilic exudate in the lavage fluid.