IGHE and food allergy: Preselection by questionnaires for students and parents. Clinical evaluation in eligible students by SPT and OFC in case of SPT result with wheal size of at least 3 mm. Current clinical food allergy was defined by positive OFC or convincing history including data on IgE sensitization (SPT wheal size of > 3 mm orsIgE > 0.35 kUA/L), or SPT with wheal size of > 8 mm.