To compare subjective and psychophysical olfactory outcomes in patients with eosinophilic chronic rhinosinusitis controlled after primary functional endoscopic sinus surgery (FESS) alone versus those treated with dupilumab for post-operative recurrence.

This retrospective cohort study included 357 adults undergoing primary FESS. Patients were classified into a FESS group (disease controlled after surgery alone, n = 334) and a dupilumab group (post-operative recurrence treated with dupilumab without revision surgery, n = 23). Subjective olfaction was assessed using the self-administered odour questionnaire and psychophysical function was assessed using standardised olfactory threshold testing. Pre- and post-treatment outcomes were compared within and between groups.

Baseline age, sex, asthma prevalence and psychophysical thresholds did not differ significantly. The Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis scores, blood eosinophils and self-administered odour questionnaire scores were worse in the dupilumab group at baseline. Both groups showed significant improvement after treatment, with no significant differences in post-treatment outcomes.

Dupilumab for post-operative recurrence achieved olfactory improvement comparable to primary FESS alone.