Shellfish Allergy Overview from Doctor Mehta in New Orleans, LA (2024)

FAQs

What is the most common shellfish allergy? ›

Allergy to crustaceans is more common than allergy to mollusks, with shrimp being the most common shellfish allergen for both children and adults.

Allergenic tropomyosins are found in invertebrates such as crustaceans (shrimp, lobster, crab, crawfish), arachnids (house dust mites), insects (co*ckroaches), and mollusks (e.g. squid), whereas vertebrate tropomyosins are nonallergenic.

Tropomyosin, a major muscle protein, is the only well-recognized allergen in molluscan shellfish. The allergens in oyster (Cra g 1), abalone (Hal m 1), and squid (Tod p 1) have been identified as tropomyosin.

Blood test.

A blood sample is sent to a lab to measure your immune system's response to a specific allergen. This test measures your immune system's response to shellfish proteins by measuring the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.

What causes a shellfish allergy? A shellfish allergy, or any food allergy, results from an immune system overreaction. Your immune system defends your body from invaders, such as infections. A food allergy occurs when your body identifies a food substance as a foreign invader and attacks it.

There is no clear-cut answer. Over time, allergies to milk, eggs and soy may disappear. Allergies to peanuts, tree nuts, fish and shellfish typically last a lifetime. About one-third of children and adults with a food allergy eventually outgrow the allergy.

Fish and shellfish products are not as common but can still exist in medications. Fish oil is an obvious one. Glucosamine is a common dietary supplement used for osteoarthritis. Some glucosamine supplements are made from the shells of crabs, lobster, or shrimp.

Symptoms caused by allergic reactions to seafood usually appear within minutes. Delayed reactions and exercise-induced anaphylaxis can occur, particularly after eating shellfish such as oyster, abalone, squid, and shrimp.

During a mild reaction

Take a non-drowsy antihistamine, such as loratadine (Claritin), as your doctor recommends. Be safe with medicines. Read and follow all instructions on the label.

How do I know if I'm still allergic to shellfish? ›

The most common symptom is raised red bumps of skin (hives). Other symptoms include wheezing and trouble breathing, cramps, nausea or vomiting. The best way to manage a shellfish or fish allergy is to avoid all food containing the species to which you are allergic.

Type O reacted most to dairy, eggs, gluten grains, and nightshades. Type AB reacted most to nuts and beans, seafood, eggs, and dairy; while A2B also reacted to gluten grains.

African American children are more likely to be allergic to shellfish and finfish: findings from FORWARD, a multisite cohort study. Mahboobeh Mahdavinia, MD., PhD.,¹ Mary C. Tobin, MD.,¹ Jamie L Fierstein, PhD.,² Aame B Andy-Nweye, MD.,¹ Lucy A Bilaver, PhD.,² Susan Fox, PA,¹ Andrea A.

Since cross-reactivity among crustacea is not complete, it is possible that allergy be limited to certain crustacea members. Patients should be alerted to possible inadvertent hidden exposure to the offending food, particularly in restaurants where cooking equipment or serving utensils may be used for different foods.

Tropomyosin (TM) is the major allergenic protein across all edible crustacean and mollusk species. More than 60 % of shellfish allergic patients are sensitized and react to TM, often leading to severe systemic reactions.

Fish allergies are primarily caused by parvalbumins, a type of calcium-binding protein. Other allergens that can cause fish allergy include enolases and aldolases, two enzymes, and fish gelatin. The major allergens in shellfish allergy are muscle proteins called tropomyosins.