Adverse reaction in a patient with aspirin-induced asthma treated with zafirlukast.

Asthmatic patients receiving antileukotrienes may develop hypereosinophilia as a part of a Churg-Strauss syndrome. It is unclear if this effect is directly related to the administration of antileukotrienes or a consequence of the corticosteroid-sparing effect of antileukotrienes unmasking a Churg-Strauss syndrome. We present a case of hypereosinophilia related to zafirlukast therapy. The patient did not fulfil criteria for Churg-Strauss syndrome. Symptoms and laboratory findings improved after zafirlukast was removed.