Shellfish Allergies Symptoms & Treatments Help

Shellfish allergies are caused by two classes of foods- mollusks which include clams, mussels, and oysters and crustaceans which include shrimp, lobster, and crabs. This also includes things lobster and shrimp, as well as octopus and squid. So, many people who are allergic to any shellfish are advised to avoid all shellfish.

Along with nuts, this is the next most common food cause of anaphylaxis.

Shellfish allergies are the most common type among adults in America, and they are more likely than most other allergies to manifest for the first time in adults.

For some people, even a tiny amount of shellfish can cause a serious reaction. Shellfish includes animals with shells, such as clams, lobster and shrimp, as well as octopus and squid. Shellfish includes animals with shells, such as clams, lobster and shrimp, as well as octopus and squid.

Does Iodine Allergy Also Mean a Shellfish Allergy Too?

Although certain shellfish are rich in iodine, there is no evidence that this will increase the risk of an iodine allergy, nor that people with shellfish allergies need to take precautions to avoid iodine when undergoing medical tests. Iodine is not related to the protein that causes shellfish allergies.

For some reason certain allergies get linked together even though they may be totally unrelated. This is what has happened with iodine and shellfish. There is no actual relationship between iodine allergy and the various seafood allergies.


The symptoms are different from having a reaction caused by toxins or bacteria. This type of food poisoning is common and can cause problems similar to a shellfish allergy. The difference being, it does not involve the immune system and only occurs when you eat food that has been contaminated.

Although symptoms can range from hives, vomiting or nasal congestion to more-severe and even life-threatening symptoms it is a major cause of anaphylactic shock. People have even been known to go into anaphylactic shock after breathing in airborne particles of shellfish or fish allergen in open fish markets.

The most common symptoms are:

  • Swelling of the lips, face, tongue and throat, or other parts of the body.
  • Wheezing, nasal congestion or even trouble breathing.
  • Abdominal pain, diarrhea, nausea or vomiting.
  • Hives, itching or eczema.
  • Dizziness, lightheadedness or fainting.
  • Tingling in the mouth may also occur.

The proteins that are most likely to cause a reaction are not found in the shell, and recent studies have indicated that glucosamine is safe for people with shellfish allergies; however, if you are concerned, you can try vegetarian glucosamine.

Role Of The FDA

Because shellfish are one of the eight most common allergens in the United States, they are covered by FALCPA the FDA’s Food Allergy Labeling and Consumer Protection Act . This requires that the presence of shellfish be listed on labels in clear English, either in bold type or following the list of ingredients after the word “Contains ” However, FALCPA only refers to crustaceans, and not to mollusks. Shellfish are relatively easier to avoid in the diet than most of the other most common allergens.


Different types of shellfish have high rates of cross-reactions with other types of shellfish, as noted above. The protein that most commonly causes problems, tropomyosin is also found in dust mites and cockroaches as well, and there is some evidence of cross-reactivity between shellfish and some insects.

If the same pair of tongs is used to handle different types of fish and shellfish, or if you suspect one type of fish or shellfish may have spilled over and had contact with another, you should avoid buying or consuming.

Freshwater Shellfish Dangers

If you’re like me, those of you out there with shellfish allergies may also need to avoid freshwater shellfish. Just be very careful because many things at restaurants are contaminated by shellfish cooking on the same grill.

How To Protect Yourself

Beyond not eating at some restaurants, the greatest challenge in living with this problem is likely the fact that shellfish allergies pose a greater risk of anaphylactic shock than many other food allergies. If you suffer from this, strictly avoiding shellfish and food containing shellfish is the only way to prevent a reaction.

If your doctor is able to identify exactly which type causes your allergies, then you need to eliminate that type of shellfish from your diet.

The fish and shellfish allergy necessitates not eating in seafood restaurants at a very minimum. This may include not eating where fried foods are prepared if fish and shellfish are on the menu. For the shellfish allergic, stay away from all shelled fish- crab, lobster, shrimp and snails.

Leave a Reply

Your email address will not be published. Required fields are marked *