There’s a little bit of evidence supporting the use of corticosteroids in both severe sepsis and in severe pneumonia. Severe influenza is both of these things, yet neither. Should we try corticosteroids?
Many have – but, unfortunately, few have rigorously evaluated it. This systematic review found 30 eligible studies, all of which were observational excepting one randomized trial. From this poor-quality data, associations between steroid use and increased mortality and increased hospital-acquired infection were observed. While this hardly excludes a potential benefit to steroids in selected cases of severe influenza, it certainly ought to encourage you to defer use of steroids until high-quality data supports the practice, if ever.
“Corticosteroids as Adjunctive Therapy in the Treatment of Influenza: An Updated Cochrane Systematic Review and Meta-analysis.”
https://www.ncbi.nlm.nih.gov/pubmed/31743228