According to Dr. Scott Sicherer at New York’s Jaffe Food Allergy Institute, having one food allergy can put you at a higher risk for reaction to other foods.
A person may be generally predisposed to have food allergy and be allergic to multiple, unrelated common allergens such as peanut, egg and milk. Or, a person may be allergic to multiple foods only because those foods share similar proteins. He emphasizes that being allergic to more than one member of a food “family” varies by the food group, and should bediscussed with your allergist. Sicherer describes a number of relationships among food allergies:
- The peanut allergic have only a 5 per cent chance of reacting to other legumes. The one exception, he says, is the lupin bean. European studies have shown half of people with peanut allergies react to beans from the lupin plant.
- People allergic to one tree nut have a one-in-three chance of allergy to other tree nuts. However, certain nuts tend to pair together, Sicherer says. Cashews and pistachios are similar, walnut and pecan allergies can come together, and almond and hazelnut reactions sometimes go hand in hand.
- Although tree nuts and peanuts are unrelated foods, reacting to both is common. The odds vary by study, but Sicherer says that between one-third to half of peanut-allergic people also have a tree nut allergy.
- A third of the people in the Food Allergy & Anaphylaxis Network’s peanut and tree nut allergy registry also have an allergy to egg. Allergy to chickens’ eggs also increases the likelihood of reacting to other bird eggs, such as quail.
- An allergy to one kind of shellfish puts you at a 75 per cent risk of being allergic to another crustacean.
- It you’re allergic to one type of fish, such as sole, there’s a 50 per cent chance you’ll react to other fish, like cod or bass.
- Allergies to a grain, such as wheat, put you at a 20 per cent risk of reacting to another grain, like barley.
- Twenty two per cent of the nut and peanut allergic people in the FAAN registry are also allergic to milk.
- A person allergic to cow’s milk has a 90 per cent chance of allergy to the milk of most other mammals. About 10 per cent of people who react to milk may also have a problem with beef.
- Allergy to fruit puts a person at a 50 to 90 per cent risk for reacting to other fruits, Sicherer says.