[1] St George Hosp, Emergency Dept, London SW17 0QT, England
[2] Primary Immunodeficiency Assoc, London, England
[3] Leicester Royal Infirm, Emergency Dept, Leicester, Leics, England
[4] Aintree Univ Hosp NHS Fdn Trust, Emergency Dept, Aintree, Scotland
[5] Fairfield Hosp, Dept Emergency Med, Bury, England
[6] St James Hosp, Dept Clin Immunol, Leeds LS9 7TF, W Yorkshire, England
[7] Plymouth Hosp NHS Trust, Dept Immunol, Plymouth, Devon, England