D1.83 - Asthma and multi-food allergy were risk factors for Oral Food Challenge failure

Food allergy (FA) diagnostics usually involve a careful clinical history and evidence of allergic specific IgE by skin and/or blood testing. Oral food challenges (OFCs) remain the gold standard for diagnosing food allergy. It is important to properly qualify patients and select ideal OFC candidates, so that an OFC remains a safe procedure. The aim of the study was to share our experiences with conducting OFCs in pediatric patients.

We conducted a retrospective analysis of 210 OFCs between January 1, 2014 and September 30, 2024 in our Allergy Department. Clinical data like patients’ demographics, comorbidities, results of allergy tests, previous history of anaphylaxis and outcome of OFC were evaluated. Multiple logistic regression analysis was used to explore associations between challenge outcome, severity of reaction and comorbidities.

The mean age of patients undergoing OFCs was 5.6±3.09 years, 136 (64.8% male). The foods challenged included cow’s milk protein – CMP (105, 50%), hen’s egg protein - HEP (87, 41.4%), peanuts and tree nuts (7, 3.3%), gluten (3, 1.4%) and other (8, 3.9%). The overall failure rate for all OFCs was 34.8%. In four cases patients experienced severe multisystemic reactions (less than 2% of all OFCs). Epinephrine administration was required in 3 (1.4%) patients. In failed OFCs patients experienced mostly mucocutaneous symptoms (44, 60.3%), followed by gastrointestinal (38, 52.1%) and respiratory (30, 41.1%) symptoms. Antihistamines were the most frequently administered medication type. The mean cumulative reactive dose for CMP was 0.76 g (median 0.27 g), whereas for HEP the mean cumulative reactive dose was 1.18 g (median 0.58 g). Asthma and multi-food allergy were risk factors for OFC failure (p=0.028, 95%CI [0.025, 0.975]; p=0.021, 95%CI [0.025, 0.975], respectively). After ROC curves interpretation a cutoff sIgE level of 55.5 kU/L (AUC: 0.79, sensitivity 0.56, specificity 0.91) was set for baked milk challenges and a threshold of 9.83 kU/L (AUC 0.68, sensitivity 0.69, specificity 0.63) for baked egg challenges. 

Our study confirms that OFCs are a safe and useful tool in establishing FA diagnosis. If a patient is properly qualified for such procedure, the risk of failure is relatively low and even if an OFC is failed, severe multisystemic reactions are rare. Comorbidities such as asthma and multi-food allergy may increase the risk of OFC failure.