allergy to crab

Last friday we went out to have dinner for my birthday at Joe's Crab shack and I ordered a bucket full of crab, shrimp, potato, sausage and corn.It was huge serving so while Joel is giving vaness some salmon I thought she might also like the crab.That was a huge mistake, when we woke up in the morning she has rashes all over her cheeks and body.I'm not sure if it was the crab but it was the only food that was not part of her usual diet that we fed her the day before.I guess I should be more careful in giving her seafoods because my family has a history of allergy to seafood.I'm glad it did not get worse.it is starting to fade.