Medically reviewed by Daniel More, MD A fish allergy, as opposed to a shellfish allergy, is one in which your immune system reacts abnormally to a finned fish such as tuna, halibut, or salmon. It is a ...

fish and shellfish.” 5 gut-friendly foods to keep your digestive system healthy and happy According to Lee, who is a specialist in immunology and allergy, symptoms can range from mild skin ...