Q. What is a fish allergy?A fish allergy occurs when the body reacts to a protein found in the flesh of finned fish. The body mistakenly perceives this protein as a threat and produces an antibody called IgE to neutralize the proteins. This, in turn, releases histamine and other chemicals, which is what causes the symptoms of an allergic reaction. An allergic reaction to fish can range from minor (including localized hives or itching) to very severe (including anaphylaxis - a potentially-fatal reaction which involves multiple body systems, and which requires immediate treatment with epinephrine). If you suspect that you or someone you know is having an anaphylactic reaction, call 911 immediately.
Q. I've never had allergies before - could I have developed a fish allergy?Yes - in fact, fish allergies typically develop in adulthood. According to FARE, 40 percent of fish allergic individuals experience their first reaction as an adult. So if you think you may be developing reactions to fish, it's critical to consult a board-certified allergist right away to test for whether you are at risk.
Q. How many people are affected by a fish allergy?A 2004 study published in The Journal of Allergy and Clinical Immunology found that 0.4 percent of the American population is allergic to one or more species of finned fish, and the majority of fish-allergic individuals are women. According to ACAAI (American College of Allergy, Asthma and Immunology) approximately 30 percent of fish-allergic children and 66 percent of allergic adults will react to more than one type of fish.
Q. I have a fish allergy. Do I need to avoid shellfish, too?Fish and shellfish are biologically different and do not appear to be cross-reactive. This means that shellfish should not cause a reaction in a fish-allergic individual, unless he or she is also allergic to shellfish. However, there are several reasons why someone who is allergic to fish may nonetheless need to avoid shellfish as well. One is cross-contamination: there's a high likelihood that finned fish will come in contact with shellfish in processing facilities, in the grocery store and/or in restaurants, as proprietors may not be aware of the seriousness of fish and/or shellfish allergies. For this reason, some health care providers may recommend avoiding shellfish as well. Speak to your doctor about whether or not you need to avoid shellfish.
Q. If I'm allergic to one type of fish, do I need to avoid all fish?It's possible to be allergic to one type of fish and not to others. As stated above, however, because of the vast quantity of fish species it's difficult to pinpoint exactly which fish are safe for you to consume. With the risk of cross-contamination from the fish to which you're allergic, most allergists recommend that fish-allergic individuals err on the side of caution and avoid all fish. Of course, always speak to your doctor about your personal food restrictions and never introduce a new fish into your diet without first clearing it with your doctor.
Q. Can I eat at a seafood restaurant if I'm allergic to fish?Fish protein can very easily become airborne through the cooking process leading to a reaction. Additionally, cross-contamination in seafood restaurants is nearly unavoidable. For these reasons, experts advise fish allergic individuals to avoid seafood restaurants. It's worth noting that many Ethnic restaurants (Thai, Chinese, African, etc.) could also pose a high risk due to their use of fish and fish sauces.
Q. I've heard that many GMO foods contain fish genes. Is it safe to eat these?Several GMO foods, including corn, tomatoes, and strawberries, are known to contain genes that are derived from fish. These food have been tested and appear to be safe for fish-allergic individuals. There have been no documented cases of a GMO food triggering an allergic reaction in fish-sensitive individuals. Of course, it's important to discuss with your doctor whether consuming GMO foods is safe for you.
Q. What common foods contain hidden sources of fish?Check out and print our Fish-free Cheat Sheet to learn the common and not-so-common sources of fish.
Q. I have a fish allergy. Do I need to avoid carrageenan?Carrageenan is a natural food additive that is extracted from red seaweed (also known as Irish Moss) grown off the coast of Ireland. It's frequently used as a thickener and gelling agent in the food industry, especially in vegan milk substitutes. According to FARE, carrageenan "appears to be safe for most individuals with food allergies," although it is known to cause digestive upset in many people. Ss always, speak to your doctor about any concerns you may have.
Q. Where can I learn more?Here are a few websites where you can find more information:
ACAAI - Fish Allergy
FARE - Fish Allergy
About.com - Foods to Avoid on a Fish-free Diet
Kids Health - Fish Allergy