The birch, a tree that is typical of northern European countries, can be found also throughout Italy, especially in the north.
Bet v1 is the major allergen of birch pollen, among 7 others known.
The plant belongs to the species betula verrucosa; Bet v1 is responsible for more than 95% of the IgE-specific reactivity in birch pollen allergic patients.
«Allergies can cause asthma and affect life quality»
The allergenicity of this pollen is considerable and is responsible for both upper and lower respiratory tract symptoms, such as rhinoconjunctivitis and asthma.
Moreover, these patients often suffer from the so-called oral allergy syndrome (OAS). OAS is characterised by itching of the oral cavity after eating a plant food, especially raw.
Flowering and/or allergen exposure period: March-May
Betulaceae have an early pollination (March-May) causing winter or pre-spring pollinosis.
Birch pollen allergy sufferers have allergic reactions to certain foods.
Cross-reaction occurs because many foods contain molecules that are similar to those found in birch pollen, which are recognised by the immune system also when ingested, thus triggering the reaction.
Birch has cross-reactivity with apple, peach, apricot, medlar, raspberry, strawberry, cherry, banana, walnut, hazelnut, almond, peanut, pistachio, carrot, potato, fennel, celery, parsley.
In general, OAS to apple and hazelnut is more common in birch allergy sufferers.
Less frequent, and almost always associated with apple and hazelnut allergy, is allergy to apiacae (celery, carrot and parsley).
