D1.298 - Does Previous Anaphylaxis Determine Differences between Patients Undergoing Oral Food Challenges to Cow’s Milk and Hen’s Egg?

Patients with a history of anaphylaxis are often considered at higher risk of OFC, which may affect 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.

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. Logistic regression models were used to assess the relationship between comorbidities, specific IgE (sIgE) concentration and OFC outcomes. Receiver operating characteristic (ROC) analysis evaluated diagnostic accuracy of sIgE concentrations in predicting OFC outcomes.

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; Table 1). Specific IgE concentration correlated with OFC outcomes across allergens, with casein-sIgE showing the highest discriminative performance (AUC = 0.81; Fig. 1) in children without previous anaphylaxis.

Risk factors for OFC failure differ according to anaphylaxis history. Atopic dermatitis and asthma influence OFC outcomes in distinct patient subgroups, while casein-sIgE shows the highest predictive value in children without prior severe reactions to CMP. A history of anaphylaxis should therefore be considered when selecting children for OFCs to CMP and HEWP, as it delineates distinct risk profiles for challenge failure.