A 3-year-old child presents with a barking cough, hoarse voice and inspiratory stridor at rest. He is agitated with moderate chest wall recession; SpO2 is 95% on room air. What is the most appropriate immediate treatment?AOral prednisolone onlyBNebulised adrenaline and oral dexamethasoneCIV antibioticsDNo treatment, observe onlyEHeliox therapy aloneCheck my answer