A rare adverse effect of montelukast treatment: ecchymosis.

Montelukast is a leukotriene receptor antagonist that is effective in the treatment of allergic rhinitis and asthma. We report a rare case of a 31-year-old woman with a history of allergic rhinitis and moderate persistent asthma, who experienced severe bruising on her lower extremities after starting montelukast treatment. Clinicians should be aware of the possibility of unusual bruising during montelukast therapy, and in those patients montelukast should be discontinued.