Safety of Open Food Challenges in the Office Setting

Abstract

Mankad VS, Williams LW, Lee LA, LaBelle GS, Anstrom KJ, Burks AW. Ann Allergy Asthma Immunol. 2008;100(5):469–474 PURPOSE OF THE STUDY. To examine the safety of open food challenges (OFCs) administered in an office setting. STUDY POPULATION. A total of 109 patients aged ≤18 years who underwent OFCs at the Duke University pediatric allergy-immunology clinic, excluding patients with a history of severe symptoms with previous reactions, were studied. Patient-selection criteria were based on the clinical history, results of skin-prick tests, and food-specific immunoglobulin E (IgE) levels that were much lower than those previously published levels predictive of a high likelihood of a clinical reaction. METHODS. The authors performed a retrospective medical chart review of OFCs. RESULTS. Among a total of 150 OFCs, most of which were to milk (n = 39), peanut (n = 37), and egg (n = 29), there were 40 positive test results (27% of all challenges) in 33 patients. Reactions were mild-to-moderate in 92% of the positive challenges. Cutaneous reactions occurred in 68% of the positive challenges, followed by gastrointestinal tract reactions (45%) and upper respiratory tract reactions (38%), excluding laryngeal symptoms. No patient had cardiovascular involvement, received epinephrine, or required hospitalization. Interventions included observation or antihistamine only for 92% of the positive challenges. Food-specific IgE values did not correlate with reaction severity. Of the 23 OFCs to milk, egg, and peanut without a history of clinical reactions, 8 were positive. For negative challenges, median prechallenge food-specific IgE levels approached previously published negative predictive values for these foods (1.22 kUA/L for milk, 0.96 kUA/L for peanut, and 0.65 kUA/L for egg). Negative challenge results for patients allowed the introduction of 19 different foods into the diets of 88 patients. CONCLUSIONS. The authors concluded that OFCs are a safe procedure in the office setting for patients selected on the basis of food-specific IgE levels that approach negative predictive values and a lack of adverse reactions within the previous year. REVIEWER COMMENTS. This nice report suggests that open OFCs performed by experienced practitioners in a clinic setting on carefully selected patients can be of significant benefit for patients who are tolerant to a food to avoid unnecessarily restrictive diets. Keeping in mind that the authors detected positive challenges in 4 patients with an undetectable food-specific IgE level and that there was a lack of association between the food-specific IgE level and severity of a reaction, prechallenge skin-prick tests and careful review of the clinical history should be used. Every challenge should be approached with appropriate precautions (emergency medications and equipment readily available) to treat potentially severe reactions.