Moderate shellfish allergy symptoms include:

Fish Allergy SymptomsSome of the top fish allergy symptoms are as below:
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If you suspect a shellfish allergy, make an appointment with your doctor—even when symptoms are mild. Since a shellfish allergy can worsen over time, you shouldn’t self-diagnose. Your regular doctor may refer you to an allergist for testing.
For more information on shellfish allergy symptoms .
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It is important at the outset to establish whether the adverse reaction is caused by shellfish allergy or toxicity. A detailed history is essential, with emphasis on the specific implicated type of seafood, the amount eaten, the type of symptoms, time of onset, and symptoms in other individuals who consumed the same meal. Management of food poisoning is mostly symptomatic. If you are suffering from fish allergy you may suffer any one or more of the following symptoms:
Photo provided by FlickrSymptoms of a shellfish allergy usually occur within a few minutes to an hour of ingestion and may include:
Photo provided by FlickrFish allergies may not become apparent until adulthood. Learn about the symptoms, diagnosis and treatment for fish allergies.
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Cod, salmon, trout, herring, sardines, bass, orange roughy, swordfish, halibut, and tuna are fish known to cause allergic symptoms, and oftentimes severe anaphylactic reactions.Worcestershire sauce: Contains fish (anchovies).
Steak sauce: May contain seafood.
Caesar salad: Often contains anchovies either on the salad or in the dressing.
Caviar: Made of fish eggs.
Marinara sauce: Sometimes contains anchovies.
Roe: Unfertilized fish eggs.
Surimi (a type of imitation crab popular in some Asian restaurants): Contains fish proteins for added flavoring.
Hot dogs, bologna and ham: Can contain fish flavoring (surimi).
Pizza toppings: Sometimes contains anchovies.
Fried rice and spring rolls: May contain shrimp.
Caponata (a Sicilian relish): Can contain anchovies.
Gelatin-based foods (e.g., marshmallows): May contain seafood.
Pet fish food: This dried substance is made of brine shrimp and other seafood. It can easily become airborne and, if inhaled, may trigger symptoms in some people with seafood allergies.
Pet food: Dog and cat food may contain seafood.More common reactions to a fish allergy are the same as symptoms of other food allergies which can affect the skin, the digestive system, and the respiratory system. Specifically, there could be presence of urticaria (hives), eczema, and angioedema (swelling), itching, upset stomach, loose stools, vomiting, cramps, gas, vomiting, nasal congestion, shortness of breath, wheezing, asthma, heart burn, lightheadedness, or fainting.It is recommended to always carry at least two (2) epinephrine auto-injectors at all times if you have been diagnosed with a food allergy, including allergy to finned fish. This is in case one misfires or if symptoms recur and a second dose is needed. If an epinephrine auto-injector has been used, always seek emergency medical assistance immediately. This is due to the possibility of a biphasic reaction. A biphasic reaction is when a second wave of symptoms occurs. This typically happens from 2-6 hours following the initial reaction.An acute, or serious, allergic reaction that comes on rapidly and may result in death is called “anaphylaxis.” It can have many symptoms and affect different parts of the body. Symptoms can include itching, sneezing, difficulty breathing, and blood circulation problems. As a result, it is under-recognized and under-treated. The most common trigger foods for anaphylaxis are peanuts, tree nuts, milk, eggs, fish, and crustaceans (shellfish). To reduce the risk of anaphylaxis, it is essential that you avoid your specific trigger food. If you have a history of anaphylactic reactions to food, you should always carry an epinephrine auto-injector with you.Affected fish often have a metallic or peppery taste. Symptoms usually commence within 30 minutes of eating. Because the symptoms are caused by the chemical histamine, they can be identical to an allergic reaction. The most common symptoms include flushing, itching, urticaria or hives, nausea, vomiting, abdominal cramps, dizziness, palpitations and headache. Severe episodes may result in wheezing and a drop in blood pressure.