[1] Univ Hong Kong, Li Ka Shing Fac Med, Dept Paediat & Adolescent Med, Hong Kong, Peoples R China
[2] Union Hosp, Allergy Ctr, Hong Kong, Peoples R China
[3] Univ Hong Kong, Shenzhen Hosp, Dept Paediat, Shenzhen, Peoples R China
[4] Univ British Columbia, Dept Pediat, Div Allergy & Immunol, Vancouver, BC, Canada
[5] British Columbia Childrens Hosp Res Inst, Vancouver, BC, Canada
[6] Univ British Columbia, Vancouver, BC, Canada
[7] Community Allergy Clin, Victoria, BC, Canada
[8] BC Childrens Hosp, Dept Pediat, Div Gastroenterol Hepatol & Nutr, Vancouver, BC, Canada
[9] Univ Hong Kong, Queen Mary Hosp, Li Ka Shing Fac Med, Dept Paediat & Adolescent Med, 1-F,New Clin Bldg,102 Pokfulam Rd, Hong Kong, Peoples R China