Can you have an allergic reaction after eating blue crabs?

Yes, it is possible to have an allergic reaction after eating blue crabs. Crab allergies are a type of shellfish allergy, and shellfish allergies are one of the most common food allergies. Symptoms of a crab allergy can range from mild, such as hives or itching, to severe, such as difficulty breathing or anaphylaxis. If you think you may be allergic to crabs, it is important to see a doctor to get tested and to avoid eating crabs in the future.