1 Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong.
2 Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong.
3 Allergy Centre, Hong Kong Sanatorium and Hospital, Hong Kong.
4 Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong.
5 Department of Paediatrics, Queen Elizabeth Hospital, Kowloon, Hong Kong.
6 Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong. Electronic address: tfleung@cuhk.edu.hk.