Evaluation of early laryngeal reaction at oral food challenge

Open oral food challenge (OFC) is a commonly used diagnostic method for food allergy; however, the occurrence of uncertain reactions leads to inconclusive results.

We aimed to determine the associations between mild laryngeal symptoms and positive results in open OFCs.

We retrospectively investigated medical records of high-risk children (aged 3-15 years) who had undergone open OFC for a low dose of peanuts, hen's egg, cow's milk, or wheat. The OFC result, severity of allergic reactions, and administered treatments during OFCs were compared between the subjects with and without laryngeal symptoms. The risks of a positive OFC result were assessed by using logistic univariate and multivariate analyses, with age, sex, and serum levels of total and food-specific IgE as covariates.

Among the 198 patients who underwent OFC, 25 had mild laryngeal symptoms: 8 (32%), 7 (22%), 0 (0%), and 10 (40%) in the OFC trials with hen's egg, cow's milk, wheat, and peanuts, respectively. In the peanut OFCs, univariate analyses revealed a 5-fold higher risk of a positive result (odds ratio = 5.0 [95% CI = 1.1-22.8]) in the symptomatic subjects than in the asymptomatic subjects. However, on multivariate analyses, none of the associations between the symptoms and a positive result were significant in any of the OFCs. The occurrence of anaphylaxis and adrenalin injections did not differ significantly between the symptomatic and asymptomatic subjects.

Laryngeal symptoms should be considered a warning sign for a positive OFC result in peanut OFCs, although not critical enough to stop the challenge.