title: [Clustering of food causing oral allergy syndrome in patients with birch pollen allergy].
abstract: BACKGROUND
  Birch pollen allergic patients often report oral and pharyngeal hypersensitivity to fruits and vegetables such as apples and peaches because of cross-reactivity. This phenomenon, called "oral allergy syndrome" (OAS), is sometimes accompanied by a systemic reaction and is considered to be an IgE-mediated allergy. We evaluated reciprocal relationships between food causing OAS using patient's reports and classified food in patients with birch pollen allergy.
  
  
  METHODS
  We interviewed 272 patients who had episodes of OAS and had IgE to birch pollen. Their mean age of the 198 women and 74 men was 34 years (15 to 65). We evaluated the reciprocal relationships between 14 foods frequently causing OAS-apples, peaches, cherries, kiwi, pears, melons, plums, strawberries, persimmons, tomatoes, grapes, watermelons, mangos, and bananas--classifying them by cluster analysis and kappa statistics.
  
  
  RESULTS
  The 14 foods were classified into rose-family and non-rose family. Rose-family fruits--apples, peaches, cherries, pears, plums, and strawberries-made a large cluster and were associated reciprocally. Melon and watermelon were associated. Melon and kiwi were not associated with rose-family fruits. Non-rose family foods--kiwi, melons, persimmons, tomatoes, grapes, watermelons, mangos, and bananas-made a large cluster and were partly associated.
  
  
  CONCLUSIONS
  Foodstuffs causing OAS were classified into two groups based on patient's reports. Some clusters of foodstuffs were related.
authors.affiliation: Yamamoto ENT Clinic, Sapporo.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Kohji
authors.initials: K
authors.lastname: Asakura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shirasaki
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Himi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D029662:Betula; D016000:Cluster Analysis; D005260:Female; D005502:Food / Q000145:classification; D005512:Food Hypersensitivity / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009059:Mouth Diseases / Q000209:etiology*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications*