Correlation of initial food reactions to observed reactions on challenges

Background: Food allergies occur in 2% to 3% of the pediatric population. These reactions can vary from mild cutaneous manifestations to severe life-threatening reactions. Limited information is available on which specific factors may predict the severity of subsequent reactions. Objective: To determine whether the organ system or the specific food involved in the initial allergic reaction predicts the outcome of subsequent food challenge. Methods: Retrospective review of all food sensitive children who underwent food challenges at The Children's Hospital of Philadelphia, Philadelphia, PA, in a 5-year period (n = 998 challenges). The specific food, initial symptom on presentation, and reaction on open challenges were recorded. Results: A total of 413 of 998 food challenges produced positive results. Milk, egg, and peanut were the most common foods to be associated with a positive challenge result. The most common presentation of food allergy was cutaneous followed by multiorgan reactions. Peanut, milk, and egg sensitivities were more likely to cause a multiple-organ system reaction on challenge than wheat or other foods. Patients with egg allergy were more likely to have a different reaction on rechallenge than other foods. Conclusions: Milk, egg, and peanut are the most common foods associated with food challenges. Patients will typically experience similar reaction on re-exposure to the initial reaction. However, multiple-organ system reactions can occur after any initial clinical presentation, with milk, egg, and peanut having more multiple-organ reactions than other foods.