Spergel JM, Beausoleil JL, Fiedler JM, Ginsberg J, Wagner K, Pawlowski NA. Ann Allergy Asthma Immunol. 2004;92:217–224
Purpose of the Study.
Allergic reactions from food can range from mild urticaria to fatal anaphylaxis. There are no clinical or laboratory features that can be used to predict the severity of a subsequent allergic reaction. This study evaluates whether the organ system or the specific food involved in the initial allergic reaction predicts the outcome of a subsequent oral food challenge.
All food-sensitive children with a history of a food-allergic reaction and a positive skin-test result who underwent food challenges at the Children’s Hospital of Philadelphia (Philadelphia, PA) over a 5-year period.
Open food challenges were offered to all patients with a history of food-allergic reactions and positive skin-test results. If the initial reaction was thought to be significant, the challenge was offered 1 year after their last reaction; if the initial reaction was equivocal, the challenge was performed earlier. The specific food, initial symptom on presentation, and reaction on open challenge were recorded and evaluated retrospectively.
A total of 413 of 998 food challenges were positive. Milk, egg, and peanut accounted for 83% of the positive challenges. Milk, egg, and peanut were also more likely than soy or wheat to cause a multiorgan system reaction on challenge. Patients were most likely to experience symptoms similar to those experienced during their initial presentation. Allergy-test results did not reliably predict the severity of a reaction.
Milk, egg, and peanut are the most common foods associated with food challenges. A patient typically will experience a similar reaction on reexposure to the initial allergen. However, multiorgan system reactions can occur after any initial clinical presentation, with milk, egg, and peanut causing a greater proportion of multiorgan system reactions than other foods.
Although subsequent food-allergic reactions were similar to previous ones, more severe reactions can occur. Many patients erroneously believe that subsequent reactions will automatically be more severe over time and this study dispels that notion. However, the results also support the instruction to families that subsequent reactions could be more severe. In the same context, the study results highlight the importance of educating patients on food-allergen avoidance and how to identify and treat allergic reactions, including the use of self-injectable epinephrine.