If you're allergic to a certain type of shellfish, your body overreacts to the proteins found in the flesh of the shellfish. A shellfish allergy is considered one of the most common food allergies by CNN Health. Shellfish include lobster, clams, octopus, squid and shrimp. If you're allergic to shellfish, you may be allergic to just one kind of shellfish or various kinds. MayoClinic.com recommends avoiding all shellfish if you've been clinically diagnosed with a shellfish protein allergy. Fish allergies are one of the most common causes of anaphylactic shock, a severe life-threatening allergic reaction.
Shellfish Proteins
The proteins in the shellfish are mistaken by the immune system as harmful. The body creates antibodies to neutralize the proteins from the shellfish, but in turn causes a chain-reaction of chemicals in the body that leads to common allergy symptoms, according to MayoClinic.com. The immune system malfunction can be triggered by a small amount of shellfish proteins. During the allergic reaction, mast cells release high levels of histamine to protect the body. Histamine in soft tissue causes the surrounding areas to become inflamed and irritated.
Symptoms
Symptoms from a shellfish protein allergy can range from mild to severe. Mild to moderate symptoms include: sinus congestion, sneezing, a runny nose, coughing, nausea, vomiting, diarrhea, stomach cramping, wheezing, coughing, asthma, shortness of breath, chest-tightness, skin rashes, tingling in the skin, hives and eczema. More severe symptoms may include: facial swelling, a rapid heart rate and a drop in blood pressure. CNN Health recommends calling for emergency medical care if these symptoms develop, as they can lead to death if not treated.
Elimination Diet
Your doctor may recommend implementing an elimination diet to determine which types of shellfish your body is allergic to. Remove all fish products from your diet for two weeks. After the completion of the two weeks, re-introduce various types of shellfish, one at a time, according to AskDrSears.com. Keep a log to record how your body reacts to each type of shellfish. This needs to be administered under a doctor's supervision. If you develop any severe symptoms, discontinue the diet and call your doctor immediately.
Further Testing
Further testing will help determine which types of shellfish you're allergic to. A skin test will use different proteins from different shellfish that are injected under the skin to observe how the skin reacts. Blood tests use a sample of your blood. Shellfish proteins are introduced into your blood to see if IgE antibodies form.
