We do not have adequate studies to state the general risk of chickpea allergy among children with peanut allergy. Peanut is a legume and it shares similar proteins with many other beans. However, in a U.S. study performed many years ago, only 5 percent of children with a peanut allergy had allergic reactions to other beans tested.

A tricky problem is that if you use blood or skin tests to beans for a person with a peanut allergy, about half the time the tests are positive even though 95 percent of the patients can eat the beans. The tests are affected by immune responses to shared bean proteins that are not important when it comes to allergic reactions.

Studies of chickpea and lentil allergy emanating from Mediterranean countries do note a high correlation of allergic reactions among pea, chickpea and lentil. Over two-thirds of children reactive to one of these three, reacted to another of the three. However, peanut allergy was uncommon in these children.

It appears that if a child with peanut allergy has already been tolerating peas, there is a much lower chance of having allergy to chickpea. Conversely, if peas caused a reaction, the risk of chickpea and lentil allergy is quite high.

Individual advice may vary, but if chickpea was already eaten and tolerated, there would be no reason to avoid it because of a peanut allergy. Lastly, a positive allergy test to chickpea in a person with peanut allergy does not prove an allergy and a medically supervised feeding (e.g. a food challenge) may be warranted.

Dr. Scott Sicherer is Chief of the Division of Allergy and Immunology of the Jaffe Food Allergy Institute at the Mount Sinai School of Medicine in New York. Together with Dr. Hemant Sharma, he writes “The Food Allergy Experts” column in the American Edition of Allergic Living magazine. Questions submitted below will be considered for answer in the magazine.

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.

See Also:

• Multiple Food Allergies on the Rise
• Girl with Multiple Allergies: An 11 year-old girl’s story of her multiple, difficult allergies.