How can a seafood allergy be diagnosed?

You should talk to your doctor about any symptoms that you have and when they happen. Keep track of what you ate up to 6 – 8 hours before any symptoms occurred. Your doctor might come up with a list of possible foods that might be causing you problems, and might ask you for permission for additional tests. There are 3 main tests – the elimination dietary challenge test, the RAST (radioallergosorbent test), and a skin test.

Out of the three, the elimination dietary challenge test is the most reliable way of finding out whether you are allergic to seafood. Your doctor will ask you not to eat any seafood or seafood containing foods for a while. As fumes and vapours from cooking seafood may also cause symptoms, the rest of your household might also have to stop eating seafood or stop cooking seafood for a period of time. You or your doctor will then see if your symptoms disappear while you are not exposed to seafood allergens. Your doctor may then advise you to reintroduce seafood into your diet, and will see if your symptoms start up again. If they do (and you didn't have them when you weren't eating seafood), there is a good chance you might have a seafood allergy. Elimination dietary challenges should be done in consultation with your doctor or a dietician.

A RAST (radioallergosorbent test) is done by taking a blood sample and trying to react various allergens with the chemicals (in particular, IgE) in your blood. It is done in the lab, and is quite reliable too. A skin prick test is less reliable and accurate than a RAST, and involves introducing small amounts of allergen to the skin to see if a reaction develops. If you are allergic to seafood, you might see a “wheal and flare” - an irregular, blanched area of skin surrounded by a reddened area of inflammation.

If you are found to be allergic to one type of seafood, you might be tested for allergies to other types of seafood too, as there can be a lot of cross-reaction.

Seafood allergies Guide Index:



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