Association of influenza-like illness and climatic parameters with hemoptysis.

BACKGROUND Although some authors have suggested that there is some seasonal periodicity of hemoptysis, or relation to respiratory tract infections, the association of influenza or climatic parameters with hemoptysis has been poorly investigated. Our aim was to describe the relationship between influenza and climatic parameters with severe hemoptysis that required bronchial artery embolization (BAE). METHODS All consecutive subjects with at least one episode of hemoptysis that required BAE during a 5-y period were included. We applied a general multivariable additive seemingly causal model corresponding to a lagged variable autoregressive model with the exogenous variables as monthly mean temperature, lagged monthly mean temperature (-1), and monthly mean influenza activity, and the number of embolizations as the endogenous variable. RESULTS We found a significant association between severe hemoptysis requiring BAE and low monthly mean temperature and influenza activity. Other climatic factors, such as atmospheric pressure, rainfall, relative humidity, or wind speed, failed to show significant association with the occurrence of life-threatening hemoptysis. CONCLUSIONS There is a strong long running relationship between severe hemoptysis and low monthly mean temperature. A weaker association of hemoptysis with influenza activity was also found.