Shellfish allergy is an abnormal reaction by the body’s immune system to proteins in some marine creatures. Shellfish include marine creatures with shells, such as fish, crab, oysters and lobster, in addition to octopus, squid and scallops.
Some individuals with shellfish allergy react to all shellfish; others react to only certain types. Reactions vary from mild symptoms — like hives or a sore nose — into acute and even life threatening.
If you feel you have a shellfish allergy, speak with your physician. Tests can help support that a shellfish allergy, which means that you may take action to prevent future responses.
Symptoms of Shellfish Allergy
Shellfish allergy symptoms generally develop within minutes to an hour of eating shellfish. They may include:
- Hives, itching or eczema (atopic dermatitis)
- Swelling of the lips, face, tongue and throat, or other parts of the body
- Wheezing, nasal congestion or trouble breathing
- Abdominal pain, diarrhea, nausea or vomiting
- Dizziness, lightheadedness or fainting
- Tingling in the mouth
Allergies can cause a serious, possibly life-threatening reaction called anaphylaxis. An anaphylactic reaction to alcoholism or anything else is a medical emergency which needs treatment with an epinephrine (adrenaline) injection along with a visit to the emergency area.
Symptoms and signs of anaphylaxis include:
- A swollen throat or a lump in your throat (airway constriction) that makes it difficult for you to breathe
- Shock, with a severe drop in your blood pressure
- Rapid pulse
- Dizziness, lightheadedness or loss of consciousness
Causes of Shellfish Allergy
All of food allergies are brought on by an immune system overreaction. Your immune system describes a specific shellfish protein as damaging, triggering the creation of antibodies into the shellfish protein (allergen). Next time you come in contact with the allergen, your immune system releases histamine and other substances that cause allergies.
Types of shellfish
There are several types of shellfish, each containing different proteins:
- Crustaceans include crabs, lobster, crayfish, shrimp and prawn.
- Mollusks include squid, snails, octopus, clams, oysters and scallops.
Some people are allergic to only one type of shellfish but can eat others. Other people with shellfish allergy must avoid all shellfish.
Prevention
If you have a shellfish allergy, the only way to avoid an allergic reaction is to avoid all shellfish and products that contain shellfish. Even trace amounts of shellfish can cause a severe reaction in some people.
