Foods to Avoid When You Have a Shellfish Allergy

If you're allergic to shellfish, you need to avoid all shellfish or risk a potentially severe allergic reaction, such as anaphylaxis. This may seem like a simple task if you think you only need to avoid shellfish like lobster, shrimp, calamari, and clams.

However, there are many other types of shellfish, including sea urchins and octopus, that need to be avoided. It is also important to know that people with a shellfish allergy may be able to eat fish without a reaction, and people with a fish allergy may be able to consume shellfish.

This article is a comprehensive guide to shellfish. You will learn which foods are shellfish, what restaurant and homecooked meals typically contain shellfish, and how to protect yourself when you have a shellfish allergy.

Shellfish Types That Cause Allergies

Shellfish are divided into two families—mollusks and crustaceans. It's possible to be allergic to just one of these two types of shellfish. For example, you might be allergic to crustaceans but not mollusks.

If you're allergic to one crustacean, you're likely allergic to all of them. For example, if you're allergic to crab you're likely allergic to shrimp too. However, most people who are allergic to one shellfish family are allergic to both.

For this reason, don't eat any shellfish from either family without talking to your healthcare provider about your allergy first.

Unfortunately, you can't trust food packaging to warn you about all shellfish. Food labeling laws in the United States only cover crustaceans, not mollusks. Only ingredients made from crustaceans must be identified on labels with an allergy warning. This can be a problem for people who have bad allergic reactions to mollusks.

Most food packaging will highlight (or at least list) mollusk ingredients. By carefully reading the package ingredient list, you should be able to identify mollusk-containing foods.

For example, a jar of white clam sauce almost certainly will contain clams or clam juice. You'll know to steer clear of it. And fried calamari, also known as fried squid, will include calamari.

Symptoms of Shellfish Allergy

The crustacean group causes the greatest number of allergic reactions. Shellfish allergy symptoms can include:

• Vomiting
• Stomach cramps
• Indigestion
• Diarrhea
• Wheezing
• Shortness of breath, difficulty breathing
• Repetitive cough
• Tightness in throat, hoarse voice
• Weak pulse
• Pale or blue coloring of the skin
• Hives
• Swelling, can affect the tongue and/or lips
• Dizziness
• Confusion

Diagnosing Shellfish Allergy

Diagnosing shellfish allergies can be complicated for the following reasons:

• Symptoms can vary from person to person.
• Symptoms may not be the same during every reaction.
• People may react even if they don't eat shellfish. They can react if they are close to shellfish being cooked or if their food comes in contact with shellfish.

If a shellfish allergy is suspected, your healthcare provider will likely refer you to an allergist. To make a diagnosis, allergists will usually do the following:

• Take a history of your allergy symptoms
• Perform a skin-prick test, which involves placing a drop of the allergen (allergy-triggering substance) on your skin, and then pricking your skin. If a red, itchy bump appears after 15 to 20 minutes, it confirms an allergy.
• Possibly order a blood test that indicates whether food-specific immunoglobulin E (IgE) antibodies are present in your body

Avoiding Shellfish

If you have a shellfish allergy, you'll need to be extremely careful when dining out. Shellfish are often stored together in restaurants and markets, so cross-contamination between crustaceans and mollusks can occur.

You may want to avoid seafood restaurants entirely because people with severe shellfish allergies have had allergic reactions simply from breathing in allergens from shellfish that are being steamed, fried, or boiled.

In fact, depending on the severity of your allergy, consider avoiding some types of restaurants and cuisines entirely, such as:

• Chinese, Japanese, Thai, Vietnamese, or Malaysian foods, which often include a fish sauce made from shrimp or imitation shellfish
• Cajun or Creole food, which frequently contains shrimp or other shellfish

Some restaurants may use shellfish stock as a flavoring or base for sauces or soups. Always tell your server or a restaurant manager about your allergy. Ask them if any items you're considering contain shellfish.

Recipes That Contain Shellfish

Shellfish is an ingredient in numerous recipes, although it may not always be obvious. Be on the lookout for these dishes and ingredients in restaurants. Also be careful when eating food prepared by friends or relatives:

• Bouillabaisse (a French fish soup)
• Ceviche (fish or shellfish in an acidic citrus marinade)
• Cioppino (fish stew)
• Clamato (a clam broth and tomato juice mixture sometimes used in Bloody Mary drinks)
• Crevette (the French term for shrimp)
• Scampi (contains lobster or shrimp)
• Etouffée (Cajun crawfish dish)
• Gumbo (fish and shellfish stew)
• Paella (Spanish rice dish usually made with shrimp)
• Jambalaya (Cajun rice dish often made with shrimp or crawfish)
• Nam prik (Thai fish sauce)
• Mam tom (Vietnamese fish sauce)

Tips for Eating Out

By following certain guidelines and preparation, eating out can still be a safe and enjoyable experience. Take these steps to protect yourself:

• Know the safest restaurants: Strict kosher restaurants, as well as vegan and vegetarian restaurants, will not contain shellfish or shellfish products.
• Check the menu online: Before heading out, review the menu on the restaurant website for shellfish dishes. Many restaurants include information on the most common food allergens, including shellfish. Reviewing the menu can give you a good idea about whether options look safe for you. Keep in mind this won't confirm there are no shellfish ingredients, such as in sauces and stock.
• Consider chain restaurants: Each restaurant is likely to use the same ingredients and prepare foods the same way and a growing number of them are allergy-aware. This can be a helpful option especially when you’re traveling and don't know the local restaurants.
  
• Talk with your server and chef: When you arrive, make sure your server and the chef are aware of your allergies. Ask what is in your dish and how it’s prepared. If you're not confident the wait staff fully understand your situation, speak to a manager.
• Bring a chef card: You can download a "food allergy alert chef card" from the Food Allergy Research and Education website. This wallet-sized card lists your food allergies and states that your food must be cooked in a clean and safe area to avoid cross-contamination. Ask the wait staff to show it to the chef(s) on duty.
• Always bring your rescue medication: While it's unlikely that you'll need it, always bring your rescue medication with you, such as your epinephrine autoinjector and, if applicable, any asthma medication. Carrying rescue medication can provide peace of mind so you can relax and enjoy your meal. Consider wearing medical identification, such as a bracelet or necklace that identifies your allergies.

Non-Food Sources of Shellfish

When you have a severe shellfish allergy, you also need to be aware of potential non-food sources of the allergen. These can include:

• Compost or fertilizers
• Fish food
• Pet food
• HemCon bandages (a wound dressing made from shrimp shells)
• Calcium supplements made from oyster shells or coral
• Glucosamine
• Omega-3 supplements (usually made from fish, but sometimes made from shellfish)
  

Summary

Shellfish allergy can cause severe symptoms. If you've been diagnosed with it, you'll need to carefully avoid all shellfish. This isn't always easy, since some food ingredients may not be immediately recognized as shellfish.

Carefully reading ingredient labels and understanding which sea animals are classified as shellfish can protect you from accidentally eating it. You may also need to avoid restaurants and certain cuisine that commonly use shellfish in recipes.