About 6.6 million Americans are allergic to seafood, which can include shellfish and other types of fish such as tuna, according to a study in the July 2004 issue of the "Journal of Allergy and Clinical Immunology." Seafood allergy is lifelong, and if you are allergic to tuna you may also have allergies to other fish. Allergic reactions can occur when you eat, handle or process raw tuna, or inhale vapors from cooking tuna. Symptoms range from mild to life-threatening.
Hives and Swelling
An allergic reaction to tuna may produce red, swollen, itchy welts called hives or urticaria, explains the Asthma and Allergy Foundation of America. Hives may occur within minutes of eating or handling tuna and usually last for two to four hours. Swelling around your eyes and lips may also develop. Over-the-counter antihistamine medications will treat localized hives and swelling. In some cases, your tongue or throat may become swollen and block the airways, so it is important to get medical attention immediately.
Frequent, projectile-like vomiting, together with swelling of your mouth or tongue, may be a sign of allergy if it occurs immediately after eating tuna. Other digestive symptoms include severe abdominal pain, diarrhea and difficulty swallowing. Diarrhea and vomiting are your body's way of getting rid of the offending food, and the reaction may develop within minutes and last up to two hours after eating tuna, according to the World Allergy Organization.
If you are allergic to tuna you may experience symptoms related to asthma, such as difficulty breathing, coughing, wheezing, chest tightness and shortness of breath. Breathing in cooking fumes, tuna-fish odor, or handling tuna in fish-processing plants may trigger asthma. Symptoms of allergic asthma usually develop within minutes to two hours after exposure. A delayed asthmatic response to tuna may occur three to eight hours after exposure.
If you are allergic to tuna, you may experience anaphylaxis, which is a life-threatening allergic reaction that affects your entire body. It can cause difficulty breathing and swelling of tissues such as your lips, throat, tongue or joints. Anaphylaxis develops rapidly and may recur a few hours after symptoms subside. It is potentially fatal, so you must get immediate medical attention, even if you begin to feel better.