It is very uncertain whether adjunctive steroid changes all‐cause death until hospital discharge compared with placebo (very low certainty).
Adjunctive steroid showed no clear difference in number of participants with developmental delay compared with placebo (low certainty).
Adjunctive steroid showed no clear difference in hearing loss at 2 years of age compared with placebo (low certainty).
Adjunctive corticosteroids leads to lower death at 1 month (adults) compared with no such treatment (high certainty).
Adjunctive corticosteroids leads to lower death at 3 to 4 months (adults) compared with no such treatment (high certainty).
Adjunctive corticosteroids showed no clear difference in death in hospital; children compared with no such treatment (moderate certainty).
Adjunctive corticosteroids probably leads to lower need for mechanical ventilation at 1 month compared with no such treatment (moderate certainty).
Intralesional steroid injection plus adjunctive treatment showed no clear difference in maximal mouth opening (interincisal distance) compared with intralesional steroid injection alone (low certainty).