Shellfish allergy - Diagnosis and treatment (2024)

FAQs

What is the treatment for shellfish allergy? ›

If you have a severe allergic reaction to shellfish (anaphylaxis), you'll likely need an emergency injection of epinephrine (adrenaline). If you're at risk of anaphylaxis to shellfish, your health care provider can give you a prescription in advance and explain how and when to give the injection.

To diagnose shellfish allergy, the routine workup would involve a thorough review of the patient's history, a skin prick test, and a blood test for shellfish allergens and tropomyosin. Clinicians would then assess whether an oral food challenge is necessary to confirm a diagnosis.

Most people who have a shellfish allergy have it for life. It doesn't go away over time.

Symptoms of fish or shellfish allergies vary and range from mild reactions to a severe allergic reaction (anaphylaxis). The most common symptom is raised red bumps of skin (hives). Other symptoms include wheezing and trouble breathing, cramps, nausea or vomiting.

An allergy to shellfish may develop any time during a person's life, but tends to present in adulthood. It can be caused by foods that you've eaten before with no issues. Along with fish, shellfish allergies are the most common adult-onset food allergies.

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.

Shellfish allergy symptoms generally start within minutes to an hour after eating or having contact with shellfish. They may include: Hives. Itchy, irritated skin.

If your mouth itches, or if you develop hives or a stomachache after eating crab, lobster or other shellfish, you may have a shellfish allergy, a condition that affects nearly 7 million Americans.

You may take antihistamines if you only experience mild symptoms after eating shellfish. Antihistamine is a drug or substance that suppresses the effects of histamine that is released when your body comes in contact with allergens. Just remember that antihistamines are not effective for severe allergic reactions.

What protein causes shellfish allergy? ›

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.

Shellfish Allergy Treatment with Oral Immunotherapy

The goal of oral immunotherapy is to continually expose the patient to increasing amounts of an allergen. As OIT progresses, the body is gradually desensitized and learns to adapt.

Shellfish can be an ingredient in some common sauces and condiments, such as soy sauce and Worcestershire sauce, so it is still important to read food labels to ensure safety. Shellfish is sometimes used as an ingredient in fish products, so specifically check these labels for shellfish.

IgE mediated reactions typically include immediate symptoms, such as urticaria, angioedema, dyspnea and, in some cases, anaphylaxis. There are, however, some patients who are able to consume shellfish, but later experience gastrointestinal symptoms with vomiting, abdominal cramping and diarrhea.

An anaphylactic reaction to shellfish is a medical emergency. Anaphylaxis requires immediate treatment with an epinephrine (adrenaline) injection and a follow-up trip to the emergency room. If anaphylaxis isn't treated right away, it can be fatal.

Treatment for accidental ingestion of shellfish products by allergic individuals varies depending on the sensitivity of the person. An antihistamine such as diphenhydramine may be prescribed. Sometimes prednisone will be prescribed to prevent a possible late phase Type I hypersensitivity reaction.

Run contaminated pots, pans, and utensils through a normal dishwasher cycle or wash them by hand with hot, soapy water and scrub the surfaces thoroughly. Use a sponge, scouring pad, or dish rag that has not come into contact with the allergen. Rinse and dry thoroughly with a clean towel.