title: A prediction rule for food challenge outcome in children.
abstract: BACKGROUND
  In children with food-related symptoms, a food challenge is considered as the gold standard to diagnose allergy. If food allergy could be predicted by patient history and/or diagnostic tests, the number of time-consuming and sometimes risky food challenges could be decreased. We aimed to determine questionnaire and test-based characteristics, to predict the food challenge outcome (FCO) in children referred to a tertiary centre for the evaluation of food-related symptoms.
  
  
  METHODS
  Pre-challenge standardized questionnaires, skin prick tests (SPT), and specific IgE levels (sIgE) were obtained in patients that underwent a food challenge in our hospital in 2009. Characteristics of patients with positive and negative FCO were compared, and uni- and multivariate associations between predictors and FCO were calculated. Based on the multivariate model, a risk score was developed to predict the FCO.
  
  
  RESULTS
  One hundred and twenty-nine challenges were analyzed, 41.9% had a positive outcome. Median age of both groups was 4.9 yrs (range 2.8-8.3). Patients with a positive FCO reacted faster with symptoms after allergen ingestion and had higher sIgE levels compared to children with negative FCO. A clinical risk score was developed based on the index food, 'time between allergen ingestion and complaints' and sIgE levels (range 0-10). The prognostic capacity of this model (AUC) was excellent (0.90). The very high- and low-risk groups (24% of patients) are both predicted excellent without misclassification.
  
  
  CONCLUSIONS
  Positive FCO can be predicted by the index food, time between allergen ingestion and development of symptoms, and the sIgE level.
authors.affiliation: Department of Paediatric Pulmonology and Allergology, University Medical Centre, Utrecht, Utrecht, The Netherlands. k.zomer-kooijker@umcutrecht.nl
authors.forename: Kim
authors.initials: K
authors.lastname: Zomer-Kooijker
authors.forename: Martijn G
authors.initials: MG
authors.lastname: Slieker
authors.forename: Petra A
authors.initials: PA
authors.lastname: Kentie
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Meijer
mesh_terms: D000485:Allergens; D002648:Child; D002675:Child, Preschool; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D012720:Severity of Illness Index; D012882:Skin Tests / Q000379:methods; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D007073:Immunoglobulin E