001614 - Biological Sensitization Patterns in Suspected Egg Allergy in Tunisia : A Real-Life Laboratory-Based Study

Egg allergy is one of the most common food allergies and is mainly IgE-mediated. In routine clinical practice in Tunisia, diagnosis is frequently based on clinical history, while skin prick-to-prick testing is inconsistently performed. Data describing the biological sensitization profiles of patients investigated for egg allergy in this context remain limited.This study aims to describe the biological sensitization profile of patients referred for suspected egg allergy in Tunisia, in a real-life setting largely driven by clinical history.

We conducted a retrospective descriptive study including patients referred to the Institut Pasteur de Tunis between January 2022 and December 2025 for suspected egg allergy. Serum-specific IgE to whole egg and egg components was measured using the ImmunoCAP® system. Component-resolved diagnostics (ovomucoid f233 and ovalbumin f232) were performed in selected cases according to clinical indication.

A total of 163 patients were included (mean age 36 years, range 5 months–73 years; male-to-female ratio 1.4). Specific IgE to egg white (f1) was assessed in 156 patients and was positive in 97 cases (62.2%). Molecular diagnostics were performed in 43 patients. Ovomucoid-specific IgE (f233) was positive in 11 of 12 tested patients, while ovalbumin-specific IgE (f232) was positive in 1 of 4 tested patients. Combined component analysis in 27 patients identified four sensitization profiles: dual sensitization to f233 and f232 (n=13), isolated f233 sensitization (n=2), isolated f232 sensitization (n=5, all with positive f1), and absence of component sensitization (n=7, all with negative f1). Specific IgE to egg yolk (f75) was measured in 72 patients and was positive in 35 cases (48.6%). Associated food and respiratory sensitizations suggesting cross-reactivity were observed in several patients.

In this real-life Tunisian cohort, suspected egg allergy is predominantly associated with sensitization to egg white proteins, particularly ovomucoid. In a setting where diagnosis often relies on clinical history with non-standardized skin testing, biological assessment, especially component-resolved diagnostics, provides valuable complementary information to support diagnosis and management.