Patterns of food allergen sensitization and co-sensitization in Jordan: A laboratory-based analysis.

BACKGROUND: Food allergy is an increasing global health concern, yet laboratory-based data on food allergen sensitization in Jordan remain limited. OBJECTIVE: To estimate the prevalence and burden of sensitization to common food allergens among patients undergoing serum specific IgE (sIgE) testing in Jordan, and to characterize co-sensitization patterns in routine clinical practice. METHODS: We retrospectively reviewed patients who underwent a standardized 34-food allergen sIgE panel between 2021 and 2024. Sensitization more frequently associated with clinical symptoms was defined a priori as Class ≥ 2; analyses were repeated at Class ≥ 1 as a sensitivity analysis. Patients were categorized as non-sensitized, monosensitized, oligosensitized (2-4 allergens), or polysensitized (≥ 5). Allergen-specific prevalence was estimated with Wilson 95% confidence intervals, and co-sensitization was explored using correlation matrices and hierarchical clustering. RESULTS: Among 405 patients (13,770 tests), 28.4% were sensitized to at least one food allergen (n = 115); most had no or a single positive result, whereas 6.7% (n = 27) were polysensitized. Shellfish (8.2%; 95%CI 5.8-11.4), cow's milk (7.4%; 5.2-10.5), and egg white (6.9%; 4.8-9.9) were most prevalent. No significant differences were observed by age or sex after adjustment for multiple comparisons. Co-sensitization analysis identified interpretable clusters, particularly among nuts/seeds, cereals, and selected animal-derived allergens. Similar patterns were observed at Class ≥ 1. CONCLUSIONS: These laboratory-based findings may support diagnostic testing, counseling, and allergy service planning in Jordan.