Churg-Strauss syndrome in patients receiving montelukast as treatment for asthma

Study objectives: We previously reported eight patients who developed Churg -Strauss syndrome in association with zafirlukast treatment for asthma and postulated that the syndrome resulted from unmasking of a previously, exist ing condition due to corticosteroid withdrawal and not from a different dru g effect. The availability of montelukast, a new leukotriene receptor antag onist with a different molecular structure, permitted us to test this hypot hesis. Our goals were to ascertain whether the Churg-Strauss syndrome devel oped in patients taking montelukast and other no cel asthma medications, an d to describe potential mechanism for the syndrome. Design: Case series. Setting: Outpatient and hospital practices of pulmonologists in the United States and Belgium. Patients: Four adults (one man, three women) who received montelukast as tr eatment for asthma; two women who received salmeterol/fluticasone therapy, but not montelukast. Results: Churg-Strauss syndrome developed in the four asthmatic patients wh o received montelukast. In each case, there was a long history of difficult -to-control asthma charactctized by multiple exacerbations that had require d frequent courses of oral systemic corticosteroids or high doses of inhale d corticosteroids for control. Two other, asthmatics who received fluticaso ne anti salmeterol ol but not montelukast therapy developed the same syndro me with tapering doses of oral or high doses of inhaled corticosteroids, Conclusions: The occurrence of Churg-Strauss syndrome in asthmatic patients receiving leukotriene modifiers appears to be related to unmasking of an u nderlying vasculitic syndrome that is initially clinically recognized as mo derate to severe asthma and treated with corticosteroids. Montelukast does not appear to directly cause the syndrome in these patients.