How quickly can oral steroids improve the condition of a preschool child with asthma who has been coughing non-stop for a week? [reactive airway+wheez

12-24 hours. If your child has been coughing secondary to an exacerbation of asthma, oral steroids usually begin working about 6 hours after being given. In general, most children have significant improvements in their symptoms by 24 hours. If the symptoms are not improving, you should consult the prescribing doctor to discuss other diagnoses.
48 Hours. Usually we see significant improvement in 48 hours. Most asthma episodes require 5 days of of oral steroids at an effective dose to resolve and prevent recurrence of coughing & wheezing. The dose is 1 mg/kg or 0.5 mg/lb.
Oral steroids. Oral steroids will be effective in the first 24hr. But works slowly and each day there will be imorovement. Steroids work slowly but there may be improvement in the first 24hr.