Is kiwifruit allergy a matter in kiwifruit-cultivating regions? A population-based study

Background: Although kiwifruit is known as a common cause of food allergy, population-based studies concerning the prevalence of kiwifruit allergy do not exist. We aimed to determine the prevalence and clinical characteristics of IgE-mediated kiwifruit allergy in 6-18-year-old urban schoolchildren in a region where kiwifruit is widely cultivated.

Methods: This cross-sectional study recruited 20,800 of the randomly selected 6-18-year-old urban schoolchildren from the Rize city in the eastern Black Sea region of Turkey during 2013. Following a self-administered questionnaire completed by the parents and the child, consenting children were invited for skin prick tests (SPTs) and oral food challenges (OFCs). Children with suspected IgE-mediated kiwifruit were skin prick tested with kiwifruit (commercial allergen and prick-to-prick test with fresh kiwifruit) and a pre-defined panel of allergens (banana, avocado, latex, sesame seed, birch, timothy, hazel, cat, Dermatophagoides pteronyssinus, and Dermatophagoides farinae). All children with a positive SPT to kiwifruit were invited for an open OFC. The prevalence of IgE-mediated kiwifruit allergy was established using open OFCs.

Results: The response rate to the questionnaire was 75.9% (15783/20800). The estimated prevalence of parental-perceived IgE-mediated kiwifruit allergy was 0.5% (72/15783) (95% CI, 0.39-0.61%). Of the 72 children, 52 (72.2%) were skin tested, and 17 (32.7%) were found to be positive to kiwifruit with both commercial extract and kiwifruit. The most frequently reported symptoms in kiwifruit SPT-positive children were cutaneous (n = 10, 58.8%) followed by gastrointestinal (n = 6, 35.3%) and bronchial (n = 4, 23.5%). Oral symptoms were reported in six (35.3%) children. All children who were kiwifruit positive by SPT were found positive during the oral challenge. The confirmed prevalence of IgE-mediated kiwifruit allergy by means of open OFC in 6-18-year-old urban schoolchildren living in Rize city was 0.10% (95% CI, 0.06-0.16).

Conclusion: Prevalence of parental-perceived and clinically confirmed kiwifruit allergy is not consistent. In contrast to expectations, kiwifruit allergy prevalence was low in a city where it is cultivated and highly consumed.