Risk factors for oral allergy syndrome in patients with seasonal allergic rhinitis.

BACKGROUND Oral allergy syndrome (OAS) is a unique allergic reaction to food, which is caused by cross-reactivity between proteins in fresh fruits or vegetables and pollens. Predisposing factors for OAS are not well known in patients with seasonal allergic rhinitis. OBJECTIVE Identify the probable risk factors for OAS in patients with seasonal allergic rhinitis. STUDY DESIGN One hundred and eleven consecutive patients with seasonal allergic rhinitis were included. Patients were evaluated in terms of symptom scores and skin prick test positivity scores. Prick-by-prick tests with the fresh fruit or vegetable were carried out in patients who describe oral allergy syndrome. Patients with OAS and without OAS were compared statistically. RESULTS OAS was more frequent in females than males (p=0.01). Odds ratio for gender (male/female) was 3.80 (95% confidence interval: 1.28-11.32). Within nasal symptoms, only nasal itching was related with OAS (P<0.05). The logistic regression analysis revealed a significant association between the prevalence of the OAS and age, asthma, TSS and TSTP (p<0.05). CONCLUSION Not all patients with seasonal allergic rhinitis develop OAS. It is likely that, patients with OAS have some additional risk factors other than atopy.