title: Prediction of clinical peanut allergy status among children in Hamilton, Ontario using chart review data collected during 2012-2015.
abstract: BACKGROUND
  Peanut sensitization does not necessarily indicate clinical peanut allergy, and uncertainty as to whether or not there is true peanut allergy can lead to increased anxiety and decreased quality of life for patients and their families. The gold standard for diagnosing clinical peanut allergy is the oral food challenge, but this method is time-consuming and can cause severe allergic reactions. It would therefore be beneficial to develop a tool for predicting clinical peanut allergy in peanut-sensitized individuals whose peanut allergy status is unknown so as to better determine who requires an oral food challenge for diagnosis.
  
  
  METHODS
  Two separate studies were conducted. In Study 1, we recruited 100 participants from the allergy clinic at McMaster University and community allergy outpatient clinics in the greater Hamilton area. We examined 18 different variables from participants and used univariate and multivariable logistic regression analysis to determine how well these variables, singly and in combination, were able to predict clinical peanut allergy status. In Study 2, we conducted a retrospective chart review of a second cohort of 194 participants to investigate the reproducibility of our findings. This was a matched case-control study where 97 peanut-allergic participants were gender- and age-matched to 97 non-allergic control participants.
  
  
  RESULTS
  Peanut skin prick test wheal size was the best predictor of clinical peanut allergy in both study cohorts. For every 1 mm increase in wheal size, the odds ratio of an individual having clinical peanut allergy was 2.36 in our first cohort and 4.85 in our second cohort. No other variable approached the predictive power of wheal size.
  
  
  CONCLUSIONS
  Peanut skin prick test wheal size is a robust predictor of clinical peanut reactivity. The findings of this study may be useful in guiding clinician decision-making regarding peanut allergy diagnostics.
authors.affiliation: Michael G. DeGroote School of Medicine, St Joseph's Hospital L314, McMaster University, 50 Charlton Avenue East, Hamilton, ON L8N 4A6 Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Simms
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON Canada.
authors.forename: Gary
authors.initials: G
authors.lastname: Foster
authors.affiliation: AstraZeneca Canada, Mississauga, Canada.
authors.forename: Katherine
authors.initials: K
authors.lastname: Arias
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Medicine, McMaster University, Hamilton, ON Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Larché
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Medicine, McMaster University, Hamilton, ON Canada.
authors.forename: Tosha
authors.initials: T
authors.lastname: Freitag
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, ON Canada.
authors.forename: Tina
authors.initials: T
authors.lastname: Walker
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, ON Canada.
authors.forename: Susanna
authors.initials: S
authors.lastname: Goncharova
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, ON Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Marrin
authors.affiliation: Department of Medicine, McMaster University, Hamilton, ON Canada.
authors.forename: Andreas
authors.initials: A
authors.lastname: Freitag
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, ON Canada.
authors.forename: Manel
authors.initials: M
authors.lastname: Jordana
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Medicine, McMaster University, Hamilton, ON Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Waserman
keywords: Peanut allergy; Skin prick test; Wheal size