Some unfortunate people have allergic reactions to large groups of related foods, such as dairy products or nuts. In other cases, the triggers for an unpleasant allergic reaction can be very specific. Although it's rare, you might find that you can eat several other varieties of peas and beans but not pinto beans specifically. More often, the allergy includes other legumes.
Food Allergy Basics
A food allergy occurs when your body encounters a protein in your food and mistakes it for a threat to your health, such as a virus or bacteria. This triggers a response from your immune system, flooding your body with natural defenses including antibodies and histamines. You may notice effects ranging from a mild rash to asthma, difficulty breathing or full-scale anaphylactic shock, which can be fatal.
Peanut Allergy and Beans
Allergies to beans are not common, despite their high levels of protein. However, one legume that's closely related to beans is a major allergen: peanuts. According to UCLA's Food and Drug Allergy Center, approximately 5 percent of people with peanut allergies are also allergic to other legumes. Legume allergies are most common among people of Mediterranean descent.
If you think you've had a reaction to pinto beans, see your doctor for a diagnosis or a referral. Any food allergy should be taken seriously, and it's possible you might be allergic to other legumes. It is also possible that you're having a reaction to an additive or preservative found in a specific brand of canned beans, or that your favorite dish with pintos includes an ingredient you're allergic to. This is why testing is important.
Pinto beans are tasty and nutritious, but seldom used outside of Mexican and Southwestern cooking. Avoiding restaurant and prepared foods from those traditions will usually limit your exposure to pinto beans. You might also wish to avoid vegetarian restaurants, where beans and legumes of all sorts are widely used for protein. Be wary of soups or dry soup mixes containing beans, as well as any bean dips at a buffet or social occasion.