RESUMO
BACKGROUND: The oral allergy syndrome (OAS) is a common cause of food allergy in adults. OBJECTIVE: Our objectives were to determine its frequency and to describe its clinical characteristics among Mexican subjects with nasal pollinosis. METHODS: The diagnosis of OAS was made using the clinical history and fresh food prick-by-prick tests. The sample to estimate the frequency consisted of 100 consecutive subjects with nasal pollinosis. The clinical features of OAS were described in thirty patients of this sample. RESULTS: The frequency of OAS among the subjects was 13%, the average age was 29.9 years and 26 subjects were women. The most common symptoms were oropharyngeal pruritus, followed by lip edema, starting mainly within the first minute after food ingestion. The median for the serum IgE levels was 160 UI/ml, while the mean for total eosinophils was 278. We observed that predominant sensitizing aeroallergens were trees, among them, oaks. A total of 23 different OAS-related foods was detected: peach (23 cases), apple (18 cases), pear (8 cases) and almond (7 cases). The OAS evolution time correlated significantly with the evolution time of allergic rhinitis (rho=0.49 P=0.006) and the duration of OAS symptoms (rho=0.37 P=0.05), whereas these last two variables showed an interdependent correlation (rho=0.52 P=0.003). CONCLUSIONS: The patients with nasal pollinosis have a considerable proportion of OAS. In subjects sensitized to pollen of oaks and/or alders, OAS should be suspected.