If you have a food allergy, you already know about taking extra precautions, checking labels, making special recipes, even avoiding your favorite restaurants and dishes. However, even if you avoid what you’re allergic to completely, you may still be at risk of having a reaction to another food.
While all allergens are different, many of them are fairly similar. This means that if your body recognizes one of them as a problem, it’s more likely to recognize the other allergen as a problem. If you are diagnosed with an allergy, you will need to avoid or take precautions around other foods that may make you react as well.
An allergy is a reaction to a foreign substance. For food allergies, this is usually a protein. Just because two foods are different, they may still contain very similar proteins. Your body may recognize them as being the same substance, and will have a reaction to both of them. This means that if you are allergic to a food, it’s important to be guarded about eating foods that might have similar proteins.
Most of the time, if you are allergic to more than one food, the two allergies are related. People who are allergic to one kind of shellfish are often allergic to other kinds or even all shellfish. If you are allergic to wheat gluten, you’re likely allergic to other glutens as well.
While some similar foods have similar proteins, other similar foods, or even different forms of the same food, will often not both trigger an allergy. The most common example is peanuts. While people with peanut allergies have a violent and even life-threatening response to peanuts, they are generally not allergic to different kinds of tree nuts because the proteins are dissimilar enough to be treated differently by their body. Also, they may not be allergic to all peanut products because some don’t contain the protein that triggers the reaction.
In addition to having more than one food allergy, you may also experience something called cross-reactivity. These are related allergies of seemingly unrelated substances, usually a food and something that isn’t a food at all, like tree pollen, or even latex.
If you are avoiding the food you are allergic to, but still having reactions, that doesn’t necessarily mean that you are allergic to another food. There are a few people that are so allergic to certain foods that they don’t even need to physically eat it to have a reaction. They may react to foods cooked or processed with the food they’re allergic to, transfer of the food from another person, or even just being in the same room with the problem food.
Always discuss symptoms with your doctor, whether you know the cause or not. You cannot be properly and safely treated if you don’t know the right diagnosis.