Background: Diagnosing food allergy (FA) typically involves a detailed clinical history and confirmation of allergen-specific IgE. Oral food challenges (OFCs) remain the gold standard in FA diagnosis. This study aimed to present our experience in performing OFCs in pediatric patients with particular focus on challenges performed with cow’s milk and hen’s egg. Methods: We conducted a retrospective analysis of 205 OFCs. Clinical data were evaluated and multiple logistic regression was used to identify associations between challenge outcomes, reaction severity, and comorbidities. Results: The mean age of patients was 5.7 ± 3.1 years, with 135 (65.9%) being male. The tested foods included cow’s milk protein (CMP, 103 challenges; 50.2%), hen’s egg white protein (HEWP, 84; 41.0%), peanuts (3; 1.5%), tree nuts (4; 2.0%), gluten (3; 1.5%), hen’s egg yolk (4; 2.0%), and other foods (4; 2.0%). The overall OFC failure rate was 32.2%, and five challenges (2.4%) yielded inconclusive results. The median cumulative reactive dose was 0.27 g for baked CMP and 0.58 g for baked HEWP. Most failed OFCs involved mucocutaneous symptoms (44 cases; 66.7%). Severe multisystemic reactions occurred in four patients (2.0%), all of whom required epinephrine (6.1% of positive challenges). An increased risk of OFC failure was associated with asthma (p = 0.028; 95% CI: 0.07–1.27) and multi-food allergy (p = 0.021; 95% CI: 0.14–1.67). Additionally, the coexistence of asthma and a prior history of anaphylaxis to any food was related to OFC failure (p = 0.049; 95% CI: 0.01–2.19), as was the combination of multi-food allergy and previous anaphylaxis (p = 0.043; 95% CI: 0.03–1.70). Receiver operating characteristic (ROC) curve analysis was utilized to predict outcomes of OFCs to baked milk and baked egg and determined a specific IgE (sIgE) cutoff level of 58.1 kU/L for baked milk challenges (AUC: 0.77; sensitivity: 0.588; specificity: 0.882), and 11.3 kU/L for baked egg challenges (AUC: 0.66; sensitivity: 0.692; specificity: 0.607). Conclusions: Our findings confirm that OFCs are a safe and effective tool for diagnosing FA in children. With appropriate patient selection, the risk of severe reactions remains low. Nonetheless, comorbidities such as asthma and multi-food allergy are associated with an increased likelihood of OFC failure.

Background: Oral food challenges (OFCs) are still the reference standard for confirming food allergy, yet the influence of previous anaphylaxis on challenge outcomes remains uncertain. Patients with a history of anaphylaxis are often considered at higher risk, which may affect the clinical decision-making process. This study aimed to identify predictors of OFC failure stratified by a history of anaphylaxis, given that prior investigations have predominantly considered anaphylaxis as an overall risk factor, without delineating distinct risk factor profiles according to anaphylaxis history. Methods: We conducted a retrospective evaluation of standard-of-care pediatric OFCs to cow’s milk and hen’s egg white. Eligible children had suspected or confirmed IgE-mediated allergy to cow’s milk protein (CMP) or hen’s egg white protein (HEWP) and were stratified by the presence or absence of previous anaphylaxis to the challenged food. Clinical data were compared between groups. Open OFCs were conducted under inpatient supervision with full emergency support. Logistic regression models were used to assess the relationship between comorbidities, specific IgE (sIgE) concentrations and OFC outcomes. Receiver operating characteristic (ROC) analysis evaluated diagnostic accuracy of sIgE concentrations in predicting OFC outcomes. Results: The analysis included 192 pediatric patients undergoing OFCs: 106 to CMP and 86 to HEWP. Six challenges (3.1%) were inconclusive, giving 186 valid results. The overall OFC failure rate was 32.3%. Patients with a past history of anaphylaxis more frequently underwent cow’s milk challenges (p = 0.01). Atopic dermatitis was a more common comorbidity in those without prior anaphylaxis (p = 0.04), regardless of the trigger. In hen’s egg challenges, children with a history of anaphylaxis reacted to significantly lower cumulative doses (p = 0.03) than patients without. Atopic dermatitis was identified as a predictor of OFC failure in children without prior anaphylaxis (p = 0.02), and asthma as a borderline predictor in those with previous systemic reactions (p = 0.05). Specific IgE concentrations correlated with OFC outcomes across allergens, with casein-sIgE showing the highest discriminative performance (AUC = 0.81) in children without previous anaphylaxis. Conclusions: Atopic dermatitis and asthma were identified as potential risk factors influencing OFC outcomes, depending on the patient’s history of anaphylaxis. The predictive accuracy of sIgE was different in groups stratified by presence of prior anaphylaxis, and the relationship between sIgE concentration and clinical reactivity was not identical across the two subpopulations. Casein-sIgE showed the highest diagnostic accuracy in children without previous severe reactions to CMP. Presence of anaphylactic reactions in the past is an important consideration when selecting children for OFCs to CMP and HEWP, since it delineates distinct risk factors for challenge failure in these patient populations.

Background: Gastroesophageal reflux and exercise-induced bronchoconstriction (EIB) commonly coexist with asthma, but the effect of exercise on reflux remains unclear. We aimed to assess the prevalence of abnormal impedance-detected acid exposure in children with partially controlled or uncontrolled asthma, its association with EIB, and changes in reflux parameters after an exercise challenge test (ECT). Methods: Thirty patients aged 7–18 years underwent spirometry, treadmill ECT, and 48 h multichannel intraluminal impedance-pH monitoring. EIB was defined as a ≥10% fall in FEV₁, and abnormal acid exposure as impedance-detected acid reflux lasting ≥1.2% of recording time. Results: Abnormal acid exposure was identified in 14/30 patients (46.7%), whereas EIB occurred in 6/30 (20.0%), with no significant association between them. The absolute number of reflux episodes was higher after ECT in the count-based analysis (43.0 [35.2–69.8] vs. 33.5 [21.2–54.5], p = 0.006); however, this finding was not confirmed after normalization to analyzable recording time in a sensitivity analysis. Overweight or obesity was present in 9 patients (30.0%) and correlated positively with acid exposure. BMI-for-age z-score correlated positively with acid exposure (ρ = 0.41, p = 0.025), but these findings did not remain significant after correction for multiple testing. Conclusions: Using the prespecified acid-exposure criterion, abnormal acid exposure was frequently identified in this cohort. No statistically significant association with EIB was demonstrated; however, the small number of EIB events limits definitive conclusions. The higher absolute post-ECT reflux episode count was not confirmed in a rate-based sensitivity analysis, and a causal effect of exercise on reflux cannot be established.

Background: Oral food challenges (OFCs) are still the reference standard for confirming food allergy, yet the influence of previous anaphylaxis on challenge outcomes remains uncertain. Patients with a history of anaphylaxis are often considered at higher risk, which may affect clinical decision-making process. In our study, we sought to identify predictors of OFC failure stratified by previous history of anaphylaxis. Methods: We conducted a retrospective evaluation of standard-of-care OFCs to cow’s milk and hen’s egg white performed between January 2014 and July 2025 at the Pediatric Allergy Center. Eligible participants had suspected or confirmed IgE-mediated allergy to cow’s milk protein (CMP) or hen’s egg white protein (HEWP), and were classified according to the presence or absence of previous anaphylaxis to the challenged food. Clinical data, including age, gender, allergic comorbidities, family history of atopy, and levels of specific IgE (sIgE) were obtained from medical records and compared between groups. Open OFCs were conducted according to PRACTALL guidelines (2012/2024) under inpatient supervision with full emergency support. Specific IgE levels were measured using the ImmunoCAP® assay (Phadia, Uppsala, Sweden). Logistic regression models were used to assess the relationship between comorbidities, sIgE concentrations and OFC outcomes. Receiver operating characteristic (ROC) analysis evaluated diagnostic accuracy of sIgE levels in predicting OFC outcomes. Results: The analysis included 192 pediatric patients (median age 4.75 years, 66.1% male) undergoing OFCs: 106 to CMP and 86 to HEWP. Six challenges (3.1%) were inconclusive, giving 186 valid results. The overall OFC failure rate was 32.3% (30.2% to CMP and 34.9% to HEWP). Patients with a past history of anaphylaxis more frequently underwent cow’s milk challenges (p = 0.01). Atopic dermatitis was a more common comorbidity in those without prior anaphylaxis (p = 0.04), regardless of the trigger. In hen’s egg challenges, children with a history of anaphylaxis reacted to significantly lower cumulative doses (p = 0.03) than patients without. Logistic regression analysis identified atopic dermatitis as a predictor of OFC failure in children without prior anaphylaxis (p = 0.02), and asthma as a borderline predictor in those with previous systemic reactions (p = 0.05). Specific IgE levels correlated with OFC outcomes across allergens, with casein-sIgE showing the highest discriminative performance (AUC = 0.81) in children without previous anaphylaxis. Conclusions: Atopic dermatitis and asthma were identified as potential risk factors influencing OFC outcomes, depending on the patient’s history of anaphylaxis. The predictive accuracy of sIgE was different in groups stratified by presence of prior anaphylaxis. Casein-sIgE showed the highest diagnostic accuracy in children without previous severe reactions to CMP. A prior history of anaphylaxis was associated with increased allergen sensitivity but did not predict a higher risk of severe reactions during supervised OFCs. Presence of anaphylactic reactions in the past is an important consideration when selecting children for OFCs to CMP and HEWP, since it delineates distinct risk factors for challenge failure in these patient populations.