Cross allergies: relations sometimes surprising

Cross allergies: relations sometimes surprising
Yannick, allergic to pollens of birch became sensitive to almonds… Nearly a third of the victims of allergies to pollens know the same nuisances vis-a-vis certain fruits. Allergic to latex, Stéphanie cannot eat any more of lawyer… The cross allergies have known for several years a clear progression. For better determining these relations sometimes surprising, Doctissimo takes stock.

When a person is reactive with an allergen (pollen, animals, fruits, etc), the contact with a body resembling the allergen will involve the same consequences. These allergic demonstrations without there being preliminary sensitizing are called cross allergies.

Close cross allergies
One will easily include/understand that the allergens result from close plant species, the more the cross allergies are frequent. 

Pollen-pollens
Thus pollens of several graminaceous close relations can involve cross allergic reactions:

Pollens of phéole, dactyl and ryegrass;
Pollens of corn, rye, brominates.
Food-food
Same manner in the event of food allergies, several fruits and/or vegetables can be with the dock. Thus, the allergies to several oilseeds are relatively frequent. The allergies to the she-ass or mare, goat, cow's milks are often associated, thus the substitution of the cow's milk to that of other mammals is generally not possible. The allergies cumulated to several leguminous plants are rather rare. Lastly, the allergies crossed to several shellfish and molluscs originate in the same protein, the tropomyosine. 

Group oleaginous
 Almond, hazel nut, nut, Brazil nut, cashew nut, nut of pécan, pinion, pistachio

Ombellifères
 Dill, carrots, celery, fennel, parsley, seeds of caraway, anise seeds, coriandre

Rosacées
 Apricots, cherries, strawberries, raspberries, hazel nuts, fishings, pears, apples, plums

Leguminous plants
 Groundnut, soya, pea, beans, lenses, broad beans

Table of principal allergenic food by family
AFSSA - January 2002

The subjects allergic to pollens have twice more risk to be food victims of allergies. The increase in these phenomena goes from pair with the boom of the food allergies since a score of years. Thus, whereas these cross allergies vegetable pollen-food were rare, they became relatively frequent today.

Allergies crossed to food and pollens
Associations can appear more surprising. Thus, more half of the victims of rhino-conjunctivites vis-a-vis pollens of birch, hazel tree or alder are sensitized with apple, the hazel nut and fishing.

Generally the exposure to the pneumoallergene (pollen) precedes that caused by ingestion by food. It is presented by itchings of the lips and language, a labial edema and a feeling of tingling. If ingestion continues, of the more serious demonstrations can occur: conjunctivitis, rhinitis, urticaria giant, edema of Quincke, anaphylaxie…

Discover the principal allergies crossed between pollen and food:

Pneumoallergenes
 Food

Pollen of birch
 apricot, almond, nectarine, carrot, celery, kiwi, fishing, hazel nut, nut, apple, potato

Pollen of armoise
 Dill, carrot, caraway, celery, coriandre, fennel, parsley 

Pollen of Ambroise Banane, melon, water melon
Pollen of graminaceous Peanut, tomato
Latex Apricot, lawyer, banana, sweet chestnuts, cherry, fig, fruit of passion, kiwi, papaw, buckwheat
Acarina Snails
Feathers of bird Eggs
Horse Meat of horse
Cat
 Pigmeat

How to determine the whole of these cross allergies? Tests can be practiced in the allergist but the treatment will always aim the initial allergen.

Tests of sensitizing
After the clinical investigation, the expert can resort to tests of sensitizing. Thanks to patchs or small inoculations, they make it possible to visualize on the level of the skin the allergic reaction. More and more often, the doctors are in front of various allergic reactions and must refine their diagnosis.

Attention, however, a positive reaction to the tests does not imply an allergy inevitably, i.e. a clinical demonstration. The cases of cross sensitivity are thus much more frequent than those of cross allergies. 

The treatment will always aim the initial allergen: in a certain number of cases, a desensitizing with pollens improves the situation as a whole.