Innovative Steroid Treatment to Reduce Asthma Development in Children After First-time Rhinovirus Induced Wheezing

Who May Qualify: - admitted to pediatric acute wards in the participating hospitals in Norway, Finland, Sweden. - referred for first severe wheezing episode, defined as first-time acute breathing difficulty with wheezing ever, appearing less than 7 days from onset of symptoms - one or more of the following:(a) fever, (b) hypoxia (SAT O2 \<= 92%), (c) retractions (inter-, subcostal), (d) prolonged expiration (on auscultation), (e) expiratory rhonchi (on auscultation) - evidence of rhinovirus infection by PCR-test in nasopharyngeal secretions - signed willing to sign a consent form and expected cooperation of the patients for the treatment and follow-up must be obtained and documented according to ICH GCP, and national/local regulations. Who Should NOT Join This Trial: - previous episodes with wheezing, defined as a history of acute breathing difficulty with wheezing in need of treatment at a general practitioner or at hospital, or parental information about similar breathing difficulties - gestational age \<37 weeks - chronic illness other than atopy (eczema), - previous systemic or inhaled corticosteroid treatment, - participation to another trial, - varicella infection or contact during the last 2-3 weeks, - need for intensive care unit treatment during the present infection, except for respiratory support with non-invasive methods (high flow nasal cannula ventilation, CPAP or BiPAP), - any reason why, in the opinion of the investigator, the patient should not participate (e.g. not able to comply with study procedures). - COVID-19 related disease. Always talk to your doctor about whether this trial is right for you.