Understanding the risk factors of oral food challenges in asthmatic children
Oral food challenges (OFCs) are a cornerstone of diagnosing and managing pediatric food allergies. A recent retrospective study published in Nutrients analyzes 205 OFCs performed in a single pediatric center to understand which preexisting conditions raise the likelihood of a reaction during testing. The findings emphasize that OFCs, when conducted in a controlled hospital environment with proper medical supervision, remain a safe and essential tool for confirming or ruling out food allergies in children.
Background: why OFCs matter in pediatric allergy care
Diagnosing a food allergy often starts with patient history, followed by allergy testing like specific IgE (sIgE) antibodies. Yet, no test perfectly predicts clinical reactions. OFCs—administering gradually increasing amounts of a suspected allergen under medical supervision—are considered the gold standard to determine if a child can tolerate a food. While OFCs carry a small risk of triggering an allergic reaction, their controlled setting allows clinicians to identify true tolerance and avoid unnecessary dietary restrictions.
What the study examined
The study reviewed pediatric charts from 2014 onward at a dedicated Pediatric Allergy Department. It focused on foods commonly tested in OFCs, notably cow’s milk protein (CMP) and hen’s egg, which together accounted for about 91% of challenges examined in the cohort. Researchers collected patient histories of allergic comorbidities, including asthma and multi-food allergy, along with basic demographics. Statistical analyses explored associations between preexisting conditions and OFC outcomes, employing a range of tests to assess predictive value.
Key findings: who is at higher risk of OFC failure
Overall, 32.2% of OFCs resulted in a reaction, with most events classified as mild to moderate. The most common reactions involved mucocutaneous symptoms such as hives and itching, observed in roughly two-thirds of the failed challenges. Severe, multisystemic reactions were uncommon, occurring in about 2% of cases, and all required epinephrine. The study identified two major risk factors for a failed OFC: a diagnosis of asthma and the presence of multi-food allergy.
Moreover, children who had both asthma and a history of anaphylaxis, or those with multi-food allergy plus a history of anaphylaxis, showed an even higher likelihood of OFC failure. These findings highlight that while OFCs are generally safe, certain pediatric populations warrant heightened caution, intensified monitoring, and careful patient selection to minimize risk and maximize diagnostic value.
How sIgE testing can aid safety without over-predicting tolerance
Beyond clinical history, the study used sIgE levels to derive practical cutoff thresholds to estimate the likelihood of an OFC triggering a reaction. For instance, a baked milk OFC threshold around 58.1 kU/L demonstrated a useful balance of sensitivity and specificity (AUC: 0.77). Importantly, these thresholds are intended as supportive tools for risk assessment during OFCs and should not be used to predict long-term tolerance development. Clinical context remains essential.
Clinical implications: improving safety through better screening
The findings reinforce that OFCs are safe when performed with strict medical supervision and appropriate patient selection. For children with asthma or multi-food allergies, clinicians can enhance safety by:
- Conducting thorough pre-OFC evaluations and reviewing history of anaphylaxis.
- Using sIgE thresholds cautiously to stratify risk in conjunction with clinical context.
- Ensuring readiness to manage reactions, including access to epinephrine and trained professionals.
Parents play a critical role in discussing risk factors with their child’s care team and understanding that a higher risk of reaction does not imply that OFCs should be avoided, but rather that they should be tailored and supervised to protect the child’s safety while refining diagnostic accuracy.
<h2 Conclusion: balancing safety and diagnostic value in pediatric OFCs
The study confirms OFCs as a safe, valuable diagnostic tool when used in appropriately equipped settings with careful patient selection. In children with asthma or multi-food allergies, a detailed clinical history, aligned with judicious use of sIgE information, can help clinicians predict risk and optimize the safety and effectiveness of OFCs. As pediatric allergy care advances, continued refinement of screening strategies will support safer testing and better outcomes for children with complex allergic profiles.
