Oral steroids are not effective for improving olfactory function after COVID-19

Reference

Schepens EJA, Blijleven EE, Boek WM, et al. Prednisolone does not improve olfactory function after COVID-19: A randomized, double-blind, placebo-controlled trial. BMC Medicine 2022;20(1):445.

Synopsis

Previous studies have reported minimal, if any, benefit to inhaled steroids for improving olfactory function in adults recovering from COVID-19. During the fourth COVID-19 wave in the Netherlands (presumably the delta variant), these investigators identified 115 adults,18 years or older, who presented with more than 4 weeks of olfactory disorders within 12 weeks of a confirmed COVID-19 diagnosis. At baseline, confirmation of objective hyposmia or anosmia occurred in all eligible patients using a previously validated olfactory function scoring tool (Sniffin' Sticks Test [SST]). All patients also underwent nasendoscopy to eliminate other potential causes for olfactory disorders. Participants randomly received (concealed allocation assignment) prednisolone (40 mg once daily for 10 days) or matching placebo. All patients also performed twice-daily olfactory training consisting of sniffing a set of known odors. The patients and the individuals who assessed outcomes remained masked to treatment group assignment. Complete follow-up occurred for 98% of patients at 12 weeks. Using intention-to-treat analysis, no group differences occurred in the primary outcome of improved olfactory function at 12 weeks as measured by the SST. Similarly, no significant group differences occurred in any of the secondary outcomes, including taste, quality of life, or Sino-Nasal Outcome Test-22 questionnaire scores.