I think I am allergic to shrimp. Alex and I go out for sushi quite a bit, and so often afterwards I feel achey, tired, and out of sorts.
For a while I thought it might be sake, or the soy sauce, or perhaps squid. A few times recently I've had all of those but no shrimp -- and no achiness! Today, again, a full and lovely lunch (minus the shrimp), and I felt great afterwards.
I like shrimp, too. Bullocks.