[1] Mayo Clin, Dept Internal Med, Div Allerg Dis, 200 First St SW, Rochester, MN 55905 USA
[2] Gentofte Univ Hosp, Dept Dermatol & Allergy, Allergy Clin, Gentofte, Denmark
[3] Imperial Coll Healthcare NHS Trust, St Marys Hosp, Frankland Allergy Clin, London, England
[4] Mayo Clin, Dept Med, Div Allergy Asthma & Clin Immunol, Scottsdale, AZ USA
[5] Strasbourg Univ Hosp, Dept Anesthesia & Intens Care, Strasbourg, France
[6] NHS Trust, Leeds Teaching Hosp, Dept Anaesthesia, Leeds, England
[7] Univ Copenhagen, Dept Clin Med, Copenhagen, Denmark