The need for hospitalization will be decided independently of the study by an on-duty physician in the emergency room. Whether hospitalized or not, the eligible children (rhinovirus positive wheezers, n=70) will be randomly assigned (2 separate randomization lists: one for hospitalized and one for out-patients) in a double-blind fashion to receive either oral prednisolone (first dose 2 mg/kg (max 60 mg), then 2 mg/kg/d (max 60 mg/d) in 3 divided doses for 3 days, Prednisolon®, 5 mg tablets, Oy Leiras Finland Ab, Helsinki, Finland) or placebo after informed consent had been obtained. The randomization code list will be stored in the hospital pharmacy and will be revealed only after all children had completed first 2 months of the study. Separate codes for each patients will be stored in patients charts and revealed in case of emergency. The tablets and packages will be indistinguishable in appearance from those of the active drug (Oy Leiras Finland Ab, Helsinki, Finland) and be provided in numbered containers. The study drugs will be administered by nurses independent of the study or by parents. The tablets will be minced and administered with jelly or yogurt. All patients will receive nebulized albuterol 0.15 mg/kg at 2 h intervals for the first 12 h, then at 4 h intervals while in the hospital. After discharge, beta2-agonists were used on demand. The patients will receive antibiotics or nebulized epinephrine (in emergency room or hospital) on demand.