Shellfish Allergies

Who gets shellfish allergy?

Although shellfish allergy occurs more often in adults and older children, it can appear at any age and can be caused by foods that had been previously eaten without any problems. Most people who are allergic to one type of shellfish are often allergic to other types of shellfish. Many people with shellfish allergy will not lose the allergy.

What are the symptoms?

Allergic reactions to foods usually begin within minutes to a few hours after eating the food. The severity of symptoms can vary widely from one person to another. Mildly allergic persons may have itching and a few hives while severely allergic persons may experience severe, life-threatening symptoms such as breathing problems or swelling of the throat. The symptoms of food allergy may include any or several of the following:

How do I avoid exposure?

If you have a shellfish allergy, strict avoidance of shellfish is the only way to prevent a reaction. The Food and Drug Administration (FDA) requires food manufacturers to list common food allergens on food labels in plain terms to make it easier to identify the food allergens. Food labels must clearly list eight allergens which account for almost 90 % of all food allergies: cow's milk, soy, wheat, egg, peanut, tree nuts, fish, and shellfish.

The common allergens are listed either within the ingredient list or after the list. For example, if a product contains abalone, a species of shellfish, the product's label should list the term "shellfish" either after the term abalone, or state "contains shellfish" after the list of ingredients. The FDA currently does not require manufacturers to state if the food was processed in a facility that also processes the 8 common food allergens.

Anyone allergic to shellfish should avoid the following ingredients and foods:

Other things to keep in mind if you have shellfish allergy:

How can I be prepared?



This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional health information, please contact the Center for Consumer Health Information at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771. If you prefer, you may visit or This document was last reviewed on: