[1] Finnish Inst Occupat Hlth, Occupat Hlth Unit, Helsinki, Finland
[2] Univ Helsinki, Helsinki Univ Hosp, Hosp Children & Adolescents, Helsinki, Finland
[3] Univ Helsinki, Dept Dermatol & Allergol, Helsinki, Finland
[4] Helsinki Univ Hosp HUS, Helsinki, Finland
[5] Univ Rochester, Med Ctr, Div Allergy & Immunol, Dept Pediat, Rochester, NY 14642 USA
[6] Univ Rochester, Med Ctr, Ctr Food Allergy, Rochester, NY 14642 USA