Cicadas Are Land Prawns, and Other Allergy Cross Reactions You Should Know About

As the Brood X cicada explosion continues on the east coast of the U.S., the FDA has issued a warning that if you are allergic to prawns, you may not want to try those cicada recipes that have been making the rounds. This isn’t the only surprising allergy cross-reaction out there, so here are a few more to pay attention to if you have allergies.

But first, some background: These cross-reactions occur because when your body learns to attack one specific item (like a protein found in seafood), it may also attack similar allergens found elsewhere (like a protein found in cicadas). Technically, cicadas are not particularly closely related to prawns — if there are any taxonomists reading this, please put down your knives — but there’s enough of a similarity between their proteins that your immune system can get confused.

Remember, if you have serious allergies or other health concerns, talk to your allergist about whether you need to avoid certain types of foods or take extra precautions.

Latex and bananas

Natural rubber latex comes from the sap of a tropical tree. Products made from this sap include latex gloves and other medical supplies; latex paint is usually not made from the tree.

Banana trees contain allergens that are similar enough to those in latex that if you are allergic to latex, you may react to bananas as well. The American College of Allergy, Asthma, and Immunology also warns that people with latex allergy sometimes also have allergies to apple, avocado, carrot, celery, chestnut, kiwi, melons, papaya, raw potato, or tomato.

Birch pollen and apples

Birch trees release their pollen in the spring, although they’re not the only cause of springtime allergies. (A variety of other plants, especially other trees, also bloom at this time). If you’re allergic to birch pollen, you are more likely to have oral allergy syndrome (OAS), which can cause your mouth to tingle or swell when you eat certain fruits. Heat can destroy the proteins that cause this reaction, so you may find that it’s uncomfortable to eat fresh apples but that you are fine with apples that have been cooked in a pie.

Aside from apples, other fruit allergies that are more common if you have a birch allergy include almonds, apricots, carrots, celery, cherries, hazelnuts, kiwis, parsley, peach, peanuts, pears, plums, and soy.

Ragweed pollen and melons

Autumn allergies can trigger OAS too, but with different fruits. Ragweed, one of the most common allergies, is linked to oral allergy syndrome with banana, cucumber, canteloupe, honeydew melon, watermelon, potatoes, and zucchini.

Cow’s milk and goat’s milk

Not all milks are alike, but some of them are. Kids With Food Allergies notes that among people who are allergic to cow’s milk (the main thing labelled as “milk” in the U.S.), only 5% will be allergic to mare’s or donkey’s milk, but 90% will have an allergy to goat’s or sheep’s milk.

Crustaceans and crickets

Cricket protein is a real thing — yes, for humans to eat — and some say it’s the food of the future. (Our friends at Gizmodo aren’t so sure, though.) As with cicadas, crickets share some allergenic proteins with crustaceans like crab, lobster, and shrimp, so if you’re allergic to seafood you may want to avoid eating crickets or cricket powder-based snacks.

Fish and… other fish

If you’re allergic to one specific type of fish, chances are 50/50 that you’re allergic to at least one other type of fish. (Salmon, tuna, catfish, and cod are among the most common fish allergies.) Fortunately, fish allergies don’t often overlap with shellfish allergies, so you may still be able to find some seafood you can eat.

Peanuts and other nuts

Peanuts are legumes, not nuts, in case you didn’t know. Kids With Food Allergies states that people with a peanut allergy will often test positive for allergies to other legumes (such as beans and lentils), but that 95% of the time, it’s a false alarm and those other legumes will be safe to eat. (Consult your allergist on this, of course.)

Tree nuts are a different story: 35% of toddlers with a peanut allergy also have a tree nut allergy. It’s not known whether this is because of a cross-reactivity between allergens or just that peanut allergies and tree nut allergies are fairly common and tend to occur in the same people.

Dust mites and shellfish

If you’re “allergic to dust,” you’re probably actually allergic to dust mites, tiny arachnids that live in our carpets and pillows and other places we’d rather not think about. They contain the same tropomyosin proteins as shellfish and cockroaches, so if you’re allergic to dust mites you might have a shellfish allergy as well.

Grass pollen and tomatoes

Oral allergy syndrome is back, and this time it’s grass pollen causing a sensitivity to several grains — which you might have guessed — as well as tomatoes. Yep, if your mouth feels tingly and itchy when you eat tomatoes, it may be because of your grass pollen allergy. You may also notice the same symptoms when you eat peaches, celery, melons, or potatoes.