Abstract
BACKGROUND AND OBJECTIVES: Food allergies are a growing public health concern, with cross-reactivity complicating diagnosis and management. Cross-reactivity occurs when immune responses to one allergen trigger reactions to similar proteins in other allergens. There is a lack of regional data on the prevalence and patterns of food allergen cross-reactivity in Saudi Arabia, particularly in the Makkah region. This study investigates the prevalence and patterns of food allergen cross-reactivity among adults in Makkah, considering gender- and age-related differences. METHODS: A cross-sectional survey was conducted between July and October 2021 among 93 adults aged 18 years or older residing in the Makkah region who self-reported doctor-diagnosed food allergies. Participants were recruited through an online questionnaire distributed via social media. The survey, validated by expert reviewers and pretested for clarity, collected demographic information, allergen types, and cross-reactivity data. Descriptive statistics, chi-square tests, and a cross-reactivity matrix were used to assess allergen co-sensitization patterns and demographic associations. RESULTS: The study identified high rates of nut, egg, and fruit allergies, with significant cross-reactivity, particularly among participants allergic to nuts. Females reported higher allergy prevalence of cross-reactivity (65.6%) compared to males (34.4%), aligning with global trends. Middle-aged females exhibited the highest rates of allergen cross-reactivity. The most frequent cross-reactivity was observed in participants with nut (100%), egg (90.7%), and fruit (89.2%) allergies. Specifically, 90.9% of individuals allergic to nuts experienced cross-reactivity with more than two other allergens. The cross-reactivity matrix revealed both expected (e.g., between tree nuts and peanuts) and unexpected patterns (e.g., between fruits and seafood), suggesting the possible influence of panallergens, co-sensitization, or regional dietary factors. CONCLUSIONS: This study highlights a high prevalence of food allergen cross-reactivity among adults in the Makkah region, with significant gender- and age-related trends. The findings underscore the need for clinician awareness of atypical and panallergen-driven cross-reactivity to support tailored patient counseling and management strategies. Region-specific screening protocols and culturally informed public health campaigns are recommended to address local dietary practices and improve allergy awareness. Future longitudinal and interventional studies incorporating objective diagnostic tools are essential to validate these findings and assess the effectiveness of targeted interventions. These insights can inform clinical guidelines and national health policies to improve diagnosis, treatment, and patient education in Saudi Arabia.