We sincerely thank Dr. Ukwaja1 for his commentary on our CMAJ article.2 To the best of our knowledge, no sign, symptom or test has been identified that can accurately differentiate viral from bacterial infection in patients with clinically diagnosed acute rhinosinusitis. Clinical practice guidelines’ recommendations to differentiate between viral and bacterial acute rhinosinusitis based on illness pattern and/or duration of symptoms are mostly based on consensus rather than scientific evidence. To enhance the generalizability of our trial findings, we included the broad population of patients with clinically diagnosed acute rhinosinusitis encountered in primary care.2
Both our primary and secondary outcomes revealed small but clinically unimportant differences between the systemic corticosteroid and the placebo group. We are therefore confident that our main conclusion “lack of effect of systemic corticosteroids in patients with clinically diagnosed acute rhinosinusitis” is justified. However, we agree with Ukwaja’s final statement that there may be a subgroup of patients who do benefit from systemic corticosteroids. The magnitude of the effect size found in our study is in agreement with the effect sizes reported in previous trials on antibiotics in acute rhinosinusitis.3 There might be a subgroup of patients that could benefit from antibiotics and an individual patient-data meta-analysis has been performed.3 Unfortunately, no clinical sign or symptom could be detected to predict beneficial effects of antibiotics. Finding subgroups of patients who really benefit from antibiotics is challenging, and it is likely that this will also be the case for detecting subgroups who will benefit from systemic corticosteroids. Future research is needed to identify those subgroups that do benefit from either antibiotics or corticosteroids. Until then, we recommend refraining from these treatment options in patients with uncomplicated clinically diagnosed acute rhinosinusitis, because symptoms are self-limiting in the majority of patients within 2 to 4 weeks.