An allergic response occurs when the over active immune system can not distingish the difference between pollen proteins and food proteins. Sometimes foods in the same botanical family, will also cause reactions. This cross reactivity is referred to as clusters of hypersensitivity . Other symptoms may include gingivitis, conjunctivitis, or rhinitis. In rare instances, asthma or anaphylaxis may be triggered.
Symptoms normally appear within minutes of eating the offending food.
The foods involved include lentils, tomatoes, apricot, peach, pear, cherry, apple, walnut, and hazelnut. Hazel nuts, almonds and walnuts are also associated. Alder pollen allergy cross reacts with celery, pears, apples, almonds, cherries, hazel nuts, peaches, and parsley. The foods known to cross react with ragweed pollen are watermelon, cantaloupe, honey dew, zucchini, banana and cucumber. Even dandelions or chamomile tea can cause a reaction because they belong to the same plant family.