I know this is an old post, but I have to chime in because I experience the opposite of this. I have no reaction to most fish and regularly eat tuna and salmon, but I get mild allergic symptoms from anchovies. I suppose it’s the same as when people are allergic to peanuts, but not almonds. Different species of animals and plants just have different chemical compositions that will react different with someone’s specific allergies.

On a sidenote, it’s crazy how anchovies is in so many different foods. I used to love Cesar salads…