Birch pollen allergy and oral allergy syndrome

Allergic rhinitis is defined as a symptomatic disorder of the nose, triggered by allergen exposure via immunoglobulin E (IgE)-mediated inflam-matory mechanisms. Symptoms include rhinorrhoea (runny nose), itching, sneezing and nasal blockage. Allergic rhinitis has a huge impact on the lives of its sufferers and is a global health problem (Bousquet et al, 2001). Its prevalence is increasing and around 15% of adults and 20% of children now suffer from allergic rhinitis, often accompanied by conjunctivitis and asthma (Strachan, 1995).