Reactive airways dysfunction syndrome.

Abstract

Reactive airways dysfunction syndrome (RADS) is an asthma-like bronchoconstriction state which develops after a short-term exposure to highly irritating volatile substances. Although some of the clinical manifestations can be considered as very similar to those of asthma (e. g. inflammation, hyperresponsiveness and reversibility of the bronchial constriction) the most essential difference lies in the absence of asthma attacks after exposure to small amounts of causative agents few weeks after onset. Thus, the mechanism of RADS cannot be considered to be of an allergic origin. This is supported by the results of the pathomorphologic biopsies taken from bronchi which usually show neutrophilic and lymphocytic infiltrations as well as frequent and severe destruction of the bronchial epithelium. Eosinophilic infiltrations and basement membrane thickness have never been found. The therapy of severe dyspnoea attacks is similar to that of bronchial asthma. Factors that cause RADS comprise a wide range of volatile irritant substances, provided that they occur in high concentrations. Exposure to isocyanates in plumbers heating polyurethane pipes seems to be the major cause of RADS in Poland.