Assessment of oral allergy syndrome in patients with seasonal allergic rhinitis by food challenge test

Oral allergy syndrome (OAS) characterized by oral IgE-mediated symptoms، which is caused by cross-reactivity between proteins in pollens، fresh fruit and vegetables. OAS is presents in 40% to 80% of Allergic rhinitis patients. Association between oral allergy syndrome and duration of seasonal allergic rhinitis is not well known. Early treatment of Patients with OAS caused improvement in quality of life and relief of their symptoms. In this prospective cross-sectional study between March 2012 to September 2012، 103 consecutive patients with seasonal allergic rhinitis were entered to this study. Their sensitizations to common aeroallergens were confirmed by skin prick test (SPT) by three mm more than negative control. According to food allergy history and prick-to-prick test results، we considered 63 of 103 patients for single-blind oral food challenge test. Data analyzed bty SPSS software (ver 11. 5)، and by Chi squeare test and paired T test. P-value lower than 0. 05 was considered as significant. Among studied cases، 63 patients (61. 2%) with 28. 8±10. 6 years old had OAS and 40 (38. 8%) with 26. 8±13. 2 years old not OAS. We found that there was significant difference between duration of seasonal allergic rhinitis in OAS group (7±5. 9 years) and non-OAS group (5±4 years) (P=0. 03، CI=0. 03-0. 04). This syndrome was more in women and patients who had concomitant asthma and allergic conjunctivitis but statistical association was not significant. This study showed that all of the patients with hay fever do not develop OAS. Duration of seasonal allergic rhinitis was associated significantly with oral allergy syndrome. However، further studies with more sample size and double-blind placebo controlled methods might be needed.