Churg-Strauss syndrome associated with montelukast

A 47 year old woman who had a history of asthma for 15 years referred to our hospital because of infiltrates on her chest radiograph that not responded to antibiotic treatment. We found that she had eosinophilia in peripheral blood (38%) and bronchoalveolar lavage (54%), nasal polyposis, and transient pulmonary infiltrates, and in the base of these findings we diagnosed as Churg-Strauss Syndrome (CSS). She has been using montelukast for 2 years. By examining her previous medical records, we observed that while eosinophil rates in peripheral blood were normal before montelukast usage, after this therapy eosinophil rates were greater 10 percent. Therefore, we thought that CSS was to be associated with montelukast usage. After just montelukast therapy was discontinued, clinical and radyographic parameters and the eosinophil counts (20%) improved. We present this case of CSS associated with montelukast in whom spontaneous remission was observed without using corticosteroids and cytotoxic agents.