Anisakis

Tick bite or not, no matter where they live, a national survey of emergency rooms found shellfish was by far the most frequently implicated food, and unlike many other allergies, kids don't tend to outgrow fish and shellfish allergies.

And many fish allergens, allergies are actually allergies not to the fish, but to worms within the fish, like Anisakis.

Exposure to these parasites, living or dead in fish, is a widespread problem.

In fact, you can even have an allergic reaction to the parasitic fish worm eating chickens that were fed on fish meal.

This is one of the ways someone who's allergic to fish could get triggered by just eating chicken.

Reminds me of pork-cat syndrome, where your mouth can get all itchy eating bacon in people with cat allergies because an allergic cross-reaction between cat skin and pig blood proteins.

Anisakis worms are, uh, found particularly in cod, anchovies, and squid, and can also cause chronic hives and intractable chronic itching.

Because of these worms, researchers recommend that people stop eating all seafood, sushi altogether because besides inducing allergenic reactions, the worms may cause a leaky gut syndrome, which often is unrecognized and can predispose to other, more important pathologies than just, uh, being itchy all over.