Shellfish Allergy

A shellfish allergy is a type of food allergy. Shellfish are animals that live in the water and have a shell-like exterior. There are two types of shellfish:

• Crustaceans: shrimp, crayfish, crab, lobster.
• Mollusks: clams, scallops, oysters, mussels.

What fish is shellfish?

If you have a shellfish allergy, don’t eat these ingredients and foods:

• Abalone.
• Clams (such as cherrystone, littleneck, pismo, quahog).
• Cockle.
• Conch.
• Crab.
• Crawfish and crayfish.
• Lobster.
• Mollusks.
• Mussels.
• Octopus.
• Oysters.
• Scallops.
• Shrimp and prawns.
• Snails.
• Squid (calamari).

Do all shellfish cause the same allergic reaction?

Often, if you have an allergy to one type of shellfish, you’ll have an allergy to other types. Crustaceans cause more allergic reactions than mollusks. But, just because you react one way to one type of shellfish doesn’t mean you’ll react the same way to every single type.

You might have a reaction after eating lobster, for example, but eat scallops without a problem. If you have symptoms after eating shellfish, talk with your healthcare provider before eating any other type of shellfish.

Is a shellfish allergy the same as shellfish intolerance?

An allergist can figure out if you’re allergic to shellfish or have an intolerance. The difference matters. While a food intolerance causes uncomfortable symptoms that mainly affect your stomach or digestive system, an allergy can affect your entire body and be life-threatening.

Who gets shellfish allergies?

Anyone can develop a shellfish allergy — even if you’ve had shellfish before without any problems. Although it can occur at any age, it appears more often in adults than in children. About 60% of people who have a shellfish allergy first get symptoms as an adult. The reason may be that children typically don’t eat shellfish. People often eat shellfish for the first time as adults, which may be why symptoms appear later in life.

How common is a shellfish allergy?

Approximately 2% of the U.S. population (around 6 million people) has a shellfish allergy.