For life threatening acute exacerbation:

Consider oral or parenteral corticosteroids as add-on therapy:

Primary options
prednisolone

1-2 mg/kg/day orally, maximum 20 mg/day (children <2 years of age) or 30 mg/day (children 2-5 years of age) or 40 mg/day (children 6-11 years of age)

Secondary options
dexamethasone sodium phosphate

0.6 mg/kg orally/intramuscularly/intravenously once daily

OR

methylprednisolone sodium succinate

1 mg/kg intravenously every 6 hours

…

For mild to moderate exacerbation consider prednisolone