Background: Montelukast is the only available antileukotriene drug in Norway. It works against the inflammation, bronchospasm and airway oedema caused by leukotrienes. In the literature there are some reports on an association between the use of the leukotriene antagonists zafirlukast, pranlukast, montelukast and the appearance of Churg-Strauss syndrome. This rare syndrome is a systemic vasculitis characterized by allergic rhinitis, asthma and prominent peripheral blood eosinophilia.
Material and methods: This is a case report of the appearance of Churg-Strauss syndrome in a 20-year-old asthmatic woman treated with montelukast and with no recent oral corticosteroid use.
Interpretation: To our knowledge, this is the first report in a Nordic country of an association between montelukast and Churg-Strauss syndrome. Although this is a rare association, the clinicians need to be vigilant in all patients who develop systemic symptoms when starting treatment with leukotriene antagonists.