Treatment of Preschool Children With Upper Respiratory Tract Illnesses Using Azythromycin and Lower Respiratory Tract Symptoms Using Oral Corticosteroids.

This protocol is comprised of two separate, but linked, clinical trials for treating preschool-aged children with recurrent severe episodes of wheezing. The first study (APRIL) will try to prevent wheezing illness from developing using azithromycin. If a wheezing illness does occur, the second trial (OCELOT) will try to decrease the severity of symptoms using oral corticosteroids.