People who have had allergic reactions to one kind of fish or shellfish are advised to avoid all seafood, as allergy to one type of seafood often indicates an allergy to other types of seafood.

It is also important to note that people with seafood allergies do not necessarily have to eat or touch fish to have a reaction. When fish is cooked, the protein released in the steam can cause reactions in some people.

Fish is unexpectedly present in some foods, such as sauces (Worcestershire, salad dressings). It is important to check labels.