PREcision Medicine Directed Corticosteroids In Children With preSchool Wheeze

"Patients to be randomised to receive OCS based on the the result of the RSV results within their respiratory virus test. This test will be performed as a point of care (POC) test in ED.~This intervention will stratify the randomisation in a 1:1 ratio, to receive OCS or not.~NB) Whilst the respiratory pathogen test is not routine care to determine the OCS prescription, it is frequently used within this setting. Additionally both the receipt (or not the receipt) of OCS is within standard care pathway. For the purpose of the trial OCS = Dexamethasone, which is delivered as oral suspension 300mcg/kg as per standard practice within the local Trust."