Understanding Shellfish Allergy

Shellfish is one of the more well-known food allergies. This allergy is typically lifelong. About 60 percent of individuals with shellfish allergy encounter their first allergic response as adults.


There are two collections of shellfish: crustacea (such as crab, shrimp, and lobster) and mollusks (such as mussels, clams, oysters, and scallops). Crustacea cause most shellfish reactions, and these tend to be severe.

Finned fish and shellfish are not associated. Being allergic to one does not necessitate that you must avoid both.

Keep a wallet-sized reference card with you of all the scientific and technical terms of your condition wherever you go with a How to Read a Shellfish Label card.

Allergic Reactions to Shellfish
Shellfish can trigger serious and possibly life-threatening allergic responses (such as anaphylaxis). Allergic reactions can be random, and even the smallest amounts of seafood can create one.

If you have a shellfish allergy, acquire and retain an epinephrine auto-injector (such as an Auvi-Q™, EpiPen®, or Adrenaclick®) with you where ever you go. Epinephrine is the first-line medication for anaphylaxis.

Avoiding Shellfish
To avoid a reaction, it is critical that you do not eat any shellfish and shellfish products at all. Regularly read food labels and ask questions about food ingredients before eating food that you have not cooked yourself.

The majority of people who are allergic to one group of shellfish are allergic to other types. Your allergist will usually recommend you avoid all kinds of seafood. If you are allergic to a specific kind of shellfish but want to eat other shellfish, talk to your physician about further allergy testing.

Bypass seafood restaurants, where there is a high risk of food cross-contact. You should also avoid touching shellfish and going to fish markets. Being in an area where shellfish are actively prepared can put you at risk, as shellfish proteins or particles could be in the steam.

Shellfish is one of the eight major allergens that are required be listed on packaged foods sold in the U.S., as dictated by federal law.

Avoid foods that have shellfish or any of these ingredients:

  • Crawfish (crawdad, crayfish, ecrevisse)
  • Crab
  • Barnacle
  • Lobster (langouste, langoustine, Moreton Bay bugs, scampi, tomalley)
  • Krill
  • Shrimp (crevette, scampi)
  • Prawns

Your doctor may recommend you to avoid mollusks* or these ingredients:

  • Abalone
  • Clams (littleneck,cherrystone, geoduck, pismo, quahog)Cuttlefish
  • Cockle
  • Scallops
  • Limpet (lapas, opihi)
  • Mussels
  • Oysters
  • Periwinkle
  • Octopus
  • Cockle
  • Sea urchin
  • Squid (calamari)
  • Sea cucumber
  • Whelk (Turban shell)
  • Snails (escargot)

*Note: The US federal government does not demand mollusks to be completely disclosed on product labels so you will have to be careful of potential products that may have mollusks as an ingredient.

Shellfish are sometimes found in the following:

  • Cuttlefish ink
  • Glucosamine
  • Fish stock
  • Bouillabaisse
  • Seafood flavoring (e.g., crab or clam extract)
  • Surimi

What About Carrageenan?
Carrageenan, also referred to”Irish moss,” is considered not shellfish. It is a red marine algae utilized as stabilizer, anemulsifier, and thickener in several foods like dairy foods. It is harmless for most indivdiuals with food allergies.

Shellfish allergy is sometimes perplexed with iodine allergy sinceshellfish is known to include the element iodine. However iodine is not what produces the reaction in people who are allergic to shellfish. If you have a shellfish allergy, you do not need to be concered about cross-reactions with radiocontrast oriodine substance (which can comprise of iodine and is used in some radiographic therapeutic procedures).

Health Life Media Team