Timothy J Watts1, Philip H Li2, Kok Loong Ue3, Rubaiyat Haque3. 1. Department of Adult Allergy, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom. Electronic address: timothy.watts2@gstt.nhs.uk. 2. Department of Adult Allergy, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom; Division of Rheumatology and Clinical Immunology, Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China. 3. Department of Adult Allergy, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.