Food hypersensitivity among schoolchildren -prevalence, Health-Related Quality of Life and experiences of double-blind placebo-controlled food challenges

................................................................................................ iii Background ............................................................................................................................... iii Aim ............................................................................................................................................ iii Methods .................................................................................................................................... iii Results ....................................................................................................................................... iv Conclusion ................................................................................................................................. v Sammanfattning på svenska .................................................................................... vi Bakgrund ................................................................................................................................... vi Syfte ........................................................................................................................................... vi Metod ........................................................................................................................................ vi Resultat .................................................................................................................................... vii Slutsats .................................................................................................................................... viii List of Abbreviations ............................................................................. ix Original Papers ...................................................................................... x Introduction ........................................................................................... 1 Background ............................................................................................ 2 Definitions of food hypersensitivity .......................................................................................... 3 IgE-mediated food allergy ................................................................................................. 4 Non IgEmediated food allergy......................................................................................... 4 Lactose intolerance ............................................................................................................. 4 Prevalence of food hypersensitivity ........................................................................................... 5 Associated factors ...................................................................................................................... 6 Food challenges ......................................................................................................................... 7 Open food challenges .......................................................................................................... 7 Double-blind placebo-controlled food challenges ............................................................. 8 Quality of Life versus Health-Related Quality of Life ............................................................... 8 Health-Related Quality of Life instruments .............................................................................. 9 Quantitative studies about Health-Related Quality of Life among children with food hypersensitivity ......................................................................................................................... 11 Health-Related Quality of Life after food challenges ....................................................... 12 Qualitative studies about experiences of living with food hypersensitivity ............................ 13 Experiences of food challenges .......................................................................................... 13 The OLIN studies .................................................................................. 14 Rationale for the present thesis .............................................................15 Specific aims ............................................................................................................................. 15 Materials and methods ......................................................................... 16 Study area ................................................................................................................................. 16 Study design .............................................................................................................................. 17 Paper I ................................................................................................................................ 17 Paper II ............................................................................................................................. 18 Paper III ............................................................................................................................. 19 Paper IV ............................................................................................................................ 20