In this study children with recurrent wheezing (>/= 2 episodes in the last 6 months)and aged
less than 2 years will be enrolled as outpatients. They will undergo lung function evaluation
by Rint and by assessment of the flow curves at baseline and after 4 weeks of treatment with
Montelukast 4 mg/day. Symptom dairies will be filled by parents during the study period.