aSpecialist Allergy and Clinical Immunology, Royal National ENT and Eastman Hospital, London

bDepartment of Rhinology, Royal National ENT and Eastman Hospital, London, University College London Hospitals NHS Foundation Trust

cBlizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK

Correspondence to Harsha H. Kariyawasam, PhD, FRCP, Specialist Allergy and Clinical Immunology, Royal National ENT Hospital and UCLH NHS Foundation Trust, 47–49 Huntley Street, London WC1E 6DG, UK. E-mail: [email protected]