There are cross allergies between pollen and food. So,

• People with Betulaceae pollen allergy (birch, alder) frequently present an oral allergy following the consumption of raw fruits of the Rosaceae family (apple, pear, peach, nectarine, cherry, apricot, plum ..); kiwi, and certain oilseeds such as almonds or hazelnuts.
• The people allergic to mugwort pollen sometimes have cross-food allergies with vegetables from the Umbellifera family: celery, carrot, fennel, parsley, cumin, coriander, etc.
• The people allergic to grass pollen sometimes have an oral allergy following the consumption of melon and watermelon.

A person can also be allergic to two different pollens.

The most common sign is oral syndrome with itching of the lips and mouth, lip edema and a tingling sensation in the palate upon ingestion of the raw fruit or vegetable.

Generally, the allergic manifestation to pollen precedes the cross-food allergy.