Previously, the efficacy of prednisolone has only been evaluated post-hoc in rhinovirus induced early wheezing in <3 year-old-children. The prevalence of relapses within 2 months after discharge was 22% in prednisolone group and 56% in placebo group. This observation needs to be confirmed in a prospective randomized trial, which is the purpose of the current study. Prednisolone has not been found beneficial in RSV-induced early wheezing in many studies and therefore, is not recommended to these children. Neither, prednisolone is used in upper respiratory tract infections without wheezing. Short courses (up to 5 days) of prednisolone have been used for decades in the treatment wheezing illnesses and they are well tolerated. There are no data that this dosage in this patient group could cause similar long-term neurological consequences as systemic corticosteroid treatment in mechanically ventilated premature infants suffering from severe respiratory distress syndrome.