Churg-Strauss syndrome associated with montelukast therapy.

Churg-Strauss syndrome is a rare form of eosinophilic vasculitis associated with asthma. Several cases of eosinophilic conditions including Churg-Strauss syndrome have recently been reported in asthmatic patients being treated with antileukotriene receptor antagonists. However, whether these drugs have a direct pathogenic role remains controversial. We describe two patients who developed Churg-Strauss syndrome after starting treatment with montelukast.