Shellfish Allergy

This food allergy is an immune system response linked to shellfish. It happens when your immune system treats harmless shellfish proteins as if they're a danger to your body. Shellfish include crustaceans and mollusks. Some examples include shrimp, lobster and crab. Oysters, scallops and snails are shellfish, too. A person with this allergy may be allergic to one or more of them.