If You’ve Ever Vomited An Oyster, Here’s Why You May Never Be Able To Eat It Again

If you love iodine and need your little dose regularly, the end of the year period must be your favorite. Indeed, the seafood is the star dish of the moment, especially oysters. The bad news is that you can suffer from an allergic reaction overnight. Allergists call this phenomenon the SEIPA. There are many people who contract this unexpected allergy, particularly when it comes to oysters… We’ll explain!

Sudden oyster allergy? Rare, but can occur at any time

“Once you throw up an oyster it’s gone, you can never eat it again”: you must have already heard this adage. So, rumor or reality? Indeed, this allergy to this seafood is rare, but it exists and knock without warning. “SEIPA is enterocolitis syndrome (intestinal inflammation, editor’s note) induced by dietary protein”explains allergist Madeleine Epstein, for Science and Future. The syndrome is best known in infant who is having an allergic reaction to cow’s milk protein. This is also possible for eggs or fish. “The most common SEIPA in adults is triggered by oystersto the point that allergists are wondering to what extent all of the toxi-infections attributed to oysters are actually SEIPA”, continues Madeleine Epstein.

Few figures on oyster allergy

Internationally, a study reveals that 0.22% the proportion of adults are victims of SEIPA (all dietary proteins combined) against 0.55% for babies in the United States. In France, Dr. Epstein conducted the investigation and only 38 cases of SEIPA in oysters in 2019 were identified. ” A vastly underestimated number“, underlines the specialist. Indeed, if the are not declared, they are not included in the statistics. For information, the persons concerned are often women who are around 40 years old. A Canadian study from 2020 concluded the same thing: 68% of women had adult SEIPA.

Anyway, the numbers are rare for adults. Indeed, researchers have more information for babies, because they consult pediatricians. “Oysters are an occasional dish, so the allergy is quickly identified, and after a second episode most adults simply stop eating it without consulting”, specifies Madeleine Epstein.

Is it a SEIPA or not?

If you have had an allergy several times, it is surely a SEIPA. “Many people who are sick for the first time think they have simply come across an infected oyster and can therefore eat it again. But each time they are sick”, explains the allergy expert. The symptoms of the syndrome are at the level of digestion. You can have vomiting and diarrhea two hours later the consumption. “Statistically there is very little chance that you will come across an infected oyster twice in a row.”, she continues.

The vicious side of the SEIPA is that it happens like this, overnight, without a trigger. “We do not know anything”, admits Madeleine Epstein. “gastroenteritis can for example modify your digestive mucosa and reveal a latent intolerance. It’s always an accumulation of factors, but we don’t know them all and we don’t know how to regulate them..”

A misunderstood reaction

When you have a basic allergy, the food causes a production of antibodies called IgE. When you do allergy tests, it is these famous IgEs that validate your allergy. However, within the framework of the SEIPA, there is nothing. The “true“oyster or shellfish allergies, with IgE, are”very rare”, informs Madeleine Epstein. Thus, specialists think rather of an imbalance of the intestinal microbiota and also of a reaction of the immune system. ” VSis a cell-mediated reaction via T cells (through opposition to reaction by IgE, which is said to be humoral and not cellular, editor’s note), but we do not know the precise mechanism”, ends the doctor. In other words, the SEIPA has no real markersbut it is confirmed by “exclusion” other causes, especially in the absence of IgE.

Healing is not guaranteed

The infant recovers within two years. But, for the adult, this is not the case. It can last for years. The only way to know if you are still a victim of SEIPA is to consume the food in question. “But I can’t advise you”, admits Madeleine Epstein. “The only recommendation is to avoid the food.”

We may have good news to end this article. If the raw oyster is no longer possible, the cooked oyster could pass. Again, it depends on the protein that is causing you the allergy and you can’t say for sure until you test!