[1] Univ Florence, Dept Hlth Sci, Florence, Italy
[2] Meyer Childrens Hosp, Dept Pediat, Allergy Unit, Florence, Italy
[3] Kings Coll London, Sch Life Course Sci, Dept Women & Childrens Hlth, Pediat Allergy Grp, London, England
[4] Univ Perugia, Dept Med & Surg, Sect Pediat, Perugia, Italy
[5] Kings Coll London, Sch Immunol & Microbial Sci, Peter Gorer Dept Immunobiol, Pediat Allergy Grp, London, England
[6] Guys & St Thomas NHS Fdn Trust, Evelina London Childrens Hosp, Childrens Allergy Serv, London, England
[7] Guys & St Thomas NHS Fdn Trust, St Johns Inst Dermatol, Unit Pediat & Populat Based Dermatol Res, London, England
[8] Kings Coll London, London, England