Cross reactivity

Individuals who react to specific food allergens, inhalants or substances can develop an allergy to others. Such reactions may be to different foods containing the same allergen, or to an allergen with a very similar protein structure. Reactions can be either light or heavy and are known as allergic cross-reactivity.

This means that someone may suffer an allergic reaction even when avoiding the foods they know they are allergic to. If someone is allergic to peanuts, for example, they might react to soya, peas, lentils or beans – food items in the same biological family (legume).

Allergic cross-reactions can also happen between certain fruit or vegetables and latex (known as latex-food syndrome), or the pollens that cause hay fever.

If a person has a measurable reaction to a certain food with clinical diagnosis, avoiding similar foods that could trigger this reaction may be helpful.

The most well-documented cross-reactivity occurs between apple and birch pollen; however, individuals who are allergic to apple are not necessarily allergic to birch pollen. Cross-reactivity should not be assumed, and important foods should not be eliminated from the diet without appropriate testing and clinical diagnosis.

Clinical relevance

Light

Frequent occurrence

Mugwort

Possible occurence

Birch, weeping

Clinical relevance

Medium

Frequent occurrence

Birch, weeping

Possible occurence

Celery; Cherry; Cocksfoot; Mugwort; Peach; Pear; Potato; Ragweed, common; Rye-grass; Tomato

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Almond; Apple; Celery; Cherry; Hazelnut; Parsley; Peach; Pear

Clinical relevance

Light

Frequent occurrence

Birch, weeping; Lilac, common; Olive

Possible occurence

Privet, common; Ragweed, common; Timothy

Clinical relevance

Medium

Frequent occurrence

Latex

Possible occurence

Banana; Kiwi

Clinical relevance

Heavy

Frequent occurrence

Latex

Possible occurence

Avocado; Birch, weeping; Goose-foot Kiwi; Melon

Clinical relevance

Light

Frequent occurrence

Blue grass, (Kentucky); Cocksfoot; Reed, common; Ryegrass, perennial; Timothy

Possible occurence

Celery; Olive; Rape, oilseed; Rye-grass; Sunflower, common

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Almond; Apple; Apricot; Buckwheat; Carrot; Celery; Cherry; Coriander; Fennel; Hazel nut; Honey; Kiwi; Nectarine; Parsley; Parsnip; Pear; Peach; Peanut; Pepper; Plum; Potato; Prune; Spinach; Walnut; Wheat

Clinical relevance

Heavy

Frequent occurrence

Apple;  Ash, common; Beech, common; Carrot; Celery; Chestnut, sweet; Cob, hazel; Curry; Hornbeam, common; Kiwi; Oak, English; Pear; Tomato

Possible occurence

Aniseed; Banana; Elm, Scottish; Caraway seed; Chamomile, German; Cherry; Coriander; Fennel seed; Hazelnut; Latex; Lychee; Mango; Mugwort; Olive; Orange; Paprika, condiment; Parsley; Peach; Pepper; Potato; Rape, oilseed; Rye-grass; Soy beanTimothy

Clinical relevance

Heavy

Frequent occurrence

Birch, weeping; Celery; Mugwort

Possible occurence

Cucumber; Head Lettuce; Mango; Melon

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Birch, weeping; Apple; Peach

Clinical relevance

Heavy

Frequent occurrence

Canary (serinus canarius); Chicken; Duck, domestic; Goose, domestic; Hen, domestic; Parrot, African gray (psittacus erithacus); Parakeet (nmphicus hollandicus) feathers; Parakeet (Melopsittacus undulatus); Pigeon

Possible occurence

 

Clinical relevance

Heavy

Frequent occurrence

Bermuda grass; Blue grass, (Kentucky); Melon; Oat flour; Rye flour; Ryegrass, perennial; Timothy; Vernal grass, scented

Possible occurence

Apple; Meadow, fescue; Oats, common; Reed, common; Rye-grass

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Carp; Eel; Herring; Mackerel; Plaice; Salmon; Sole; Tuna fish

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Barley; Blue grass, (Kentucky); Millet; Oats, common; Soy bean; Ryegrass, perennial; Rice; Wheat, common

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Oyster; Shrimp; Squid

Clinical relevance

Light

Frequent occurrence

Celery

Possible occurence

Carrot; Melon

Clinical relevance

Medium

Frequent occurrence

Birch, weeping; Celery; Mugwort

Possible occurence

 

Clinical relevance

Medium

Frequent occurrence

Latex

Possible occurence

 

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Birch, weeping; Celery Mugwort

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Peach

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Melon; Orange; Swiss chard; Tomato; Watermelon; Wheat

Clinical relevance

Heavy

Frequent occurrence

Cob, hazel

Possible occurence

Birch, weeping; Kiwi; Mugwort; Peach; Poppy seed; Rue flour; Sesame

Clinical relevance

Medium

Frequent occurrence

Birch, weeping; Latex; Timothy

Possible occurence

Avocado; Banana; Hazelnut; Mugwort; Poppy Seed; Rye flour; Ryegrass, perennial; Sesame

Clinical relevance

Heavy

Frequent occurrence

Avocado; Banana; Edible Chestnut; Ficus benjamini (Tropic laurel, Weeping fig); Kiwi; Mango; Melon; Papaya; Tomato

Possible occurence

Apple; Birch, weeping; Buckwheat; Carrot; Celery; Dill; Fig; Mugwort; Orange; Oregano; Passion fruit; Peach; Peanut; Pear; Pineapple; Potato; Ragweed, common; Rye-grass; Sage; Soy bean; Strawberry; Timothy; Walnut

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Pea; Walnut

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Birch, weeping

Clinical relevance

Medium

Frequent occurrence

Celery; Cocksfoot; Latex; Ragweed, common

Possible occurence

Banana; Carrot; Cucumber; Goose-foot; Plantain, English; Zucchini

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Carrot; Celery; Coriander; Fennel; Melon; Parsley; Pepper; Spices; Sunflower; Watermelon

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Asparagus; Garlic; Timothy

Clinical relevance

Heavy

Frequent occurrence

 

Possible occurence

Birch, weeping

Clinical relevance

Light

Frequent occurrence

Latex

Possible occurence

 

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Birch, weeping; Celery; Mugwort

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Lentil; Mugwort; Peanut

Clinical relevance

Heavy

Frequent occurrence

Tomato

Possible occurence

Latex; Lentil; Mugwort; Parietaria; Pea; Peach; Soy bean

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Apple; Birch, weeping; Mugwort; Peach

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Celery; Birch, weeping; Mugwort

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Latex; Rye-grass

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Hazelnut; Kiwi; Rye flour

Clinical relevance

Medium

Frequent occurrence

Cat, domestic

Possible occurence

 

Clinical relevance

Light

Frequent occurrence

 

Possible occurence

Apple; Birch, weeping; Latex; Tomato

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Apple; Banana; Cantaloupe; Chamomile tea; Honey; Honeydew; Nuts; Sunflower; Watermelon

Clinical relevance

Light

Frequent occurrence

Birch, weeping; Peanut; Rye-grass; Timothy

Possible occurence

Apple; Celery; Latex; Mugwort; Potato

Clinical relevance

Medium

Frequent occurrence

 

Possible occurence

Peach