Shellfish allergies are a much greater problem than fish allergies, because it is much more common and causes a greater severity of anaphylaxis than most other allergies. Shellfish allergies are rare in children, it generally develops during adulthood and is lifelong in virtually all sufferers. Those who are allergic to one shellfish are generally allergic to all.
The Center for Disease Control (CDC) says that crustacean shellfish are one of the eight (8) foods or food groups that make up 90% of all serious allergic reactions in the United States.
Over 75% of people are allergic to all types of crustacean shellfish if they are allergic to any.
The rate of allergy to non-crustacean shellfish and other sea creatures appears lower, but there is still a risk that would need to be addressed by your allergist. Crustaceans include the following: lobster, shrimp, crab, prawns, crevettes, langoustine, crawfish, crayfish and ecrevisse. Severe allergy to these is more common than a severe allergy to the Mollusks (non-crustacean). Each crustacean can be tested individually, but in practice, those who are allergic to one crustacean are generally advised to avoid all crustaceans. Mollusks (non-crustaceans) include the following: clams, oysters,scallops and mussels. These are the mollusks that are primarily responsible for allergic reactions. Octopus, squid and snails are also mollusks, but an allergy to these is usually independent of the primary mollusks. Specific allergy tests are available for some Mollusks.
Symptoms of a shellfish allergy:
1.Tingling in the mouth
2.Abdominal pain, nausea, diarrhea and vomiting
3.Congestion, trouble breathing or wheezing
4.Skin reactions including itching, hives or eczema
5.Swelling of the face, hands, fingers,lips, tongue, throat and ears
6. Lightheadedness, dizziness or fainting