Abstract
Leukotriene receptor antagonists are a class of drugs used in maintenance therapy of asthma. Among the adverse effects induced by them, particularly by montelukast, is eosinophilic granulomatosis with polyangiitis (EGPA), which manifests as a form of vasculitis co-occurring with severe asthma and eosinophilia. Our aim was to point to the importance of this particular diagnosis by analyzing the published cases of montelukast induced EGPA and to analyze them in order to identify if this form of EGPA presented some specific characteristics. Leukotriene receptor antagonist induced EGPA is a frequent adverse event compared to EGPA induced by other drugs, and specialists should be aware of it. We observed that more than half of patients were female. Montelukast induced EGPA occurred after a variable period of time. The most common clinical manifestation was neuropathy and most of the patients had a good outcome after immunosuppressant treatment. The present diagnosis should be considered by physicians when patients are prescribed montelukast followed by worsening of symptoms.