[Meteorological conditions and spontaneous pneumothorax. Retrospective study of 165 cases in the Rouen area].

The occurrence of a spontaneous "idiopathic" pneumothorax in 165 patients admitted to hospital could be precisely dated over a 5-year period. An analysis of the meteorological conditions recorded at these dates (mean atmospheric pressure, mean temperature, relative and absolute humidity) and of their seasonal distribution demonstrated two peaks of frequency, one in the summer, the other in the winter, and a significant correlation between the occurrence of pneumothorax and a low relative humidity. These results, particularly clear during the exceptionally dry summer of 1976, confirm some data in the literature and suggest that bronchoconstriction induced by moistening of air in the airways might play a role in the pathophysiology of pneumothorax.