Competing interests: We have read and understood the BMJ policy on declaration of interests and declare no relevant financial interests. Mieke van Driel declares payment from IN VIVO Academy Ltd to develop materials for an educational programme on Medication Overuse Headache supported by a competitive unrestricted grant from Pfizer. Philippe Gevaert declared advisory board membership and paid consultancy with Sanofi which produces Dupilumab and Roche which produces Xolair, both for Chronic Rhinosinusitis with nasal polyps.