Chestnuts (not to be confused with horse chestnuts or water chestnuts, which are not related) have 4 allergenic proteins, Cas s 1, Cas s 5, Cas s 8 and Cas s 9.
Cas s 1 is a Bet v 1 allergen, so is associated with Pollen Food Allergy Syndrome.
Cas s 5 is a chitinase, this is a plant derived enzyme made by the plant to act as a defence against fungal attacks
Cas s 8 is a Lipid Transfer Protein (LTP).
Cas s 9 is a small heat shock protein.
You may have Pollen-Food Allergy Syndrome if you suffer from chestnut allergy with oral allergy symptoms to 3 or more of the foods mentioned in cross reactivity section.
Chestnut allergy is most commonly seen in conjunction with allergies to other foods presenting as Latex Food Syndrome. This is due to the high level of chitinase. Latex Food Syndrome is caused by the body confusing the proteins it encounters in food to that of latex proteins to which it is already sensitised.
LTP's are a group of proteins which can cause more serious allergic reactions in patients, you may suffer from LTP Syndrome if you suffer IgE type allergy symptoms to foods mentioned in the cross reactivity section below.
If sensitised to Birch pollen you may have Pollen Food Allergy Syndrome and may also react to Apple, Pear, Peach, Plum, Nectarine, Apricots, Cherries, Chestnut, Kiwi, Tomato, Celery, Carrot, Potato, Parsnip, Pepper, Dill, Cumin, Peas, Coriander, Fennel, Hazelnut, Walnut, Almonds, Peanuts, Lentils and Beans
Foods linked to Latex Food Syndrome may have linked allergies to foods which contain high levels of chitinase, like avocado, banana, corn (maize), kiwi, papaya, pomegranate and tomatoes.
Foods linked to LTP Syndrome are hazelnuts, almonds, walnuts, apples, dried fruit, lettuce and tomatoes. Symptoms are more intense if food is dried or concentrated.