Systemic medication requirement in post-surgical patients with eosinophilic chronic rhinosinusitis

Background: Eosinophilic chronic rhinosinusitis (eCRS) is contemporarily managed by surgical creation of a 'neo-sinus' cavity and corticosteroid irrigations. While most patients gain control of their disease with this approach, similar to preventive inhaler therapy in asthma, some patients need systemic therapies. This study aimed to define those patients needing ongoing systemic therapy for eCRS. Methods: Consecutive adult patients (>18 years) who were seen at a tertiary referral clinic, diagnosed as eCRS and underwent endoscopic sinus surgery were included. Patients were followed up for a minimum of 12 months. All patients had a simple neosinus cavity surgically created and used initially a once daily topical corticosteroid irrigation maintenance therapy. Patients who required long term systemic oral corticosteroids and/or biologic therapy were compared to those who remained on topical control. Results: 222 patients with eCRS were assessed (follow-up 2.76 years). Long term systemic therapy was required in 5.4% of patients. Receiver operating curve analysis predicted local treatment failure at an eosinophil count cut-off level 0.455x109/L. Asthma, atopy and aspirin sensitivity also predicted long term systemic therapy. There were no associations with nasal polyposis or revision surgery. Multivariate logistic regression showed elevated blood eosinophil count >0.455 x109/L was 9.27 times more likely to require for systemic medication. Conclusion: Pre-operative blood eosinophil count >0.45 x109/L was associated with failure of local therapy following contemporary management of eCRS. The quantitative value of serum eosinophilia may be a useful predictor of disease progression and those patients in need of systemic therapies, such as biologic agents.