D3.89 - Decoding a Triple Pediatric Food Allergy Phenotype Using Component-Resolved Diagnostics: Severe CMPA, Alpha-Gal, and PR-10–Mediated PFAS

Background: Pediatric polyallergy can result from overlapping primary IgE-mediated sensitizations and secondary cross-reactive pathways, complicating diagnosis and management. Conventional extract-based testing lacks resolution, while component-resolved diagnostics (CRD) enables precise molecular phenotyping and individualized care.

Case Presentation: We report a child with a rare triple-allergy phenotype: severe cow’s milk protein allergy (CMPA), alpha-gal sensitization, and PR-10–mediated pollen–food allergy syndrome (PFAS). CRD at ages 3 and 5-revealed persistently high whole-milk and casein-specific IgE up to 78 kUA/L, confirming a thermostable CMPA profile. Extensive PR-10 sensitization was identified: rBet v 1, rPru p 1, rMal d 1, rCor a 1, rGly m 4 >100 kUA/L, with negative IgE to lipid transfer proteins and profilins. α-Gal IgE was 3.6 kUA/L. Clinically, the child experienced systemic reactions to cow’s milk, oral allergy syndrome to PR-10 foods, and a severe anaphylactic reaction after yogurt and peach ingestion. CRD distinguished primary systemic allergy from secondary pollen-related cross-reactivity, guiding precise management: strict avoidance of cow’s milk and beef, emergency treatment, and birch pollen immunotherapy. Nine-month follow-up showed clinical stability with no recurrence of severe reactions.

Conclusion: This case demonstrates the pivotal role of CRD in complex pediatric polyallergy. It allows differentiation of primary IgE-mediated sensitizations from secondary cross-reactivity, supports targeted dietary management, informs allergen immunotherapy, and enhances risk stratification, ultimately optimizing safety and quality of life in children with overlapping molecular allergy profiles.