Transepidermal Water Loss in Oral Food Challenges in Children With Peanut Allergy: A Randomized Clinical Trial.

Importance: Food allergy is a prevalent chronic medical condition in children, with limited diagnostic options. Transepidermal water loss (TEWL) is a measure of skin barrier function with emerging utility in atopy and food allergy. Objective: To determine whether use of TEWL as a stopping criterion can prevent anaphylaxis during a peanut oral food challenge (OFC). Design, Setting, and Participants: This was a single-center randomized clinical trial of children aged 6 months to 5 years with a history of a clinical peanut allergic reaction and positive peanut skin prick and/or serum immunoglobulin E testing. All participants underwent peanut OFC at an allergy referral clinic. The study began May 1, 2023, and ended August 31, 2024. Intervention: The intervention was stopping OFC based on a 1 g/m2/h rise in TEWL plus 1 objective allergic symptom observed by the physician during OFC. Standard OFC stopping criteria or the intervention criteria, whichever came first, were used in the intervention group. OFC stopping criteria from standard research were used in the control group. This was a single-intervention study. Main Outcome and Measures: Rate of anaphylaxis, defined as a Consortium for Food Allergy Research (CoFAR) score of 2 or higher, compared between the intervention and control groups using 4 anaphylaxis criteria approaches: CoFAR, Brighton Collaboration, Food Allergy and Anaphylaxis Network (FAAN), and World Allergy Organization (WAO). Results: A total of 40 participants were included in the final analysis. The mean (SD) age of participants was 31.8 (16.18) months, with a median of 32.5 (range, 9-62) months; 23 (58%) were male. Using CoFAR criteria, among reactors, the anaphylaxis rate was 10 of 16 (63%; 95% CI, 39%-86%) in the intervention group compared with 14 of 14 (100%; 95% CI, 100%-100%) in the control group (P = .02). Using WAO criteria, 2 of 16 participants were reactors in the intervention group (anaphylaxis rate, 13%; 95% CI, 0%-29%) compared with 8 of 14 (57%; 95% CI, 31%-83%) in the control group (P = .02). There was no significant difference when comparing anaphylaxis rates using Brighton or FAAN criteria (eg, rate of 56% [95% CI, 32%-81%] vs 71% [95% CI, 48%-95%] in intervention vs control participants using Brighton criteria [P = .47]). The median CoFAR score in reactors in the intervention vs control groups was 1.8 (IQR, 1.0-2.0) vs 2.6 (IQR, 2.0-3.0) (P = .006). Eight of 16 participants (50%) in the intervention vs 12 of 14 (86%) in the control group required epinephrine (P = .06). Conclusions and Relevance: In this randomized clinical trial, prospective use of TEWL as a stopping criterion reduced anaphylaxis rates during OFC in children with peanut allergy, suggesting use of TEWL could make OFC safer and more accessible. Replicating this study in a larger, multicenter population is a reasonable next step. Trial Registration: ClinicalTrials.gov Identifier: NCT05696236.