A friend of mine is epi-pen levels of allergic to shellfish and they wouldn’t let him try crickets in culinary school because there’s often an overlap.
With 17 year cicadas popping up, people were eating them like shrimp. There were actually warnings put out by health agencies not to try it if you had a shellfish allergy.
Huh, TIL. I tried crickets once as a kid and don't remember having any issues with it, but I can't order cream cheese wontons from the Chinese place near my house because it's the same fryer they use for squid. I found that out after I ordered them once and had a reaction. :/ Weirdly, I used to love crab rangoon before I went vegetarian and I never had a problem with it, and I don't remember having problems the few times I've tried shrimp either. Squid has always been a problem for me though, the few times I've tried it or been exposed.
If it helps, that might be irrelevant for you! My friend mentioned that chitin was the issue (no idea if he’s right, please don’t take medical advice from me), so things like shrimp and crab are huge problems for him, but I think cephalopods less so
Yeah, in my case it might just be molluscs (or possibly just squid, but I'm probably going to avoid escargot and mussels), which is less common but possible - crustaceans only is apparently much more common, but they apparently generally associate the two because it's not unusual for both to cause problems and with serious allergies it's better to not fuck around and find out.