• Allergies

Fish Allergy: Symptoms and Tips for Managing it

Published: February 26, 2025
Updated: February 26, 2025
4 mins

Fish is a versatile, nutritious source of protein and omega-3 fatty acids. However, many people have to avoid it entirely. Some people may assume that those allergic to fish should also avoid shellfish, but this is not always the case.

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What is a Fish Allergy?

A fish allergy is an immune response to consuming finned fish like tuna, salmon, and catfish. The immune system perceives proteins like parvalbumin in fish as a threat. This leads to an allergic reaction as your body attempts to fight off harmful proteins.

Unlike other allergens, it’s common to develop a fish allergy as an adult, even if you did not have it as a child. People with parents who have a fish allergy are more likely to develop one as well.

Over 2,000 species of fish exist around the world. Some of the more popular fish species to avoid if you have an allergy include:

• Salmon

• Catfish

• Tilapia

• Trout

• Snapper

• Perch

• Flounder

• Cod

• Bass

Unexpected Sources of Fish

For those with a fish allergy, it’s important to check the ingredients in the foods you eat. It’s not always obvious that certain foods contain allergens. The FDA (Food and Drug Administration) requires manufacturers to clearly list major allergens on nutrition labels to prevent accidental exposure.

The following foods may trigger symptoms in those with a fish allergy:

• Caesar dressing

• Worcestershire sauce

• Barbecue sauce

Cross-Contamination and Safe Handling with Fish

When going out to eat, let the restaurant staff know if you have a fish allergy. Cross-contamination can occur if food without fish is cross-contaminated with fish dishes in the kitchen. 

There are steps you can take at home as well to prevent cross-contamination of fish with other seafood products if you live with someone with an allergy:

• Never use the same utensils for raw seafood and cooked seafood

• Keep seafood products in clearly labeled containers

• Try not to place seafood directly on ice in freezers

• Use gloves when handling seafood and other food products

• Make sure to wash your hands in between touching seafood and surfaces

What are the Symptoms of a Fish Allergy?

Many people with a fish allergy experience severe symptoms after consumption. However, some people may have more of a mild reaction to it. Those with a severe fish allergy may experience symptoms from the smell of fish when it is being cooked, even if they don’t eat it.

A person with a fish allergy may experience the following symptoms from exposure:

• Abdominal pain

• Trouble breathing

• Hives

• Diarrhea

• Nausea

• Vomiting

• Coughing

Symptoms may start immediately after exposure but can also occur several hours later. In severe cases, a person may experience anaphylaxis — a life-threatening allergic reaction. One of the first signs of anaphylaxis is having trouble breathing or feeling the throat close up.

A healthcare provider may recommend carrying an EpiPen (epinephrine injection) to help alleviate symptoms before receiving emergency attention.

How is a Fish Allergy Diagnosed?

The symptoms of a fish allergy mirror the symptoms of many other major allergens. Before diagnosing a fish allergy, a healthcare provider may ask you about your family health history.

A blood test can distinguish between a fish allergy and other allergens. It detects IgE antibodies related to fish allergens.

Other options include conducting an allergy skin prick test or an oral allergy test. However, skin prick tests may not detect certain fish proteins as well as a blood test. An oral allergy test can detect allergic responses by placing a small amount of allergens on the surface of the skin.

How Do You Treat a Fish Allergy?

The best way to avoid symptoms is to avoid foods containing fish. While you may not be allergic to all types of fish, healthcare providers tend to recommend avoiding all fish because of the risk of cross-contamination. 

Antihistamines can help treat mild fish allergy symptoms. However, severe reactions require stronger medication, like an EpiPen. An epinephrine injection is typically administered into the outer thigh.

Where Can I Learn More About Food Allergies?

Food allergies can drastically change the experience of eating out at a restaurant. At LifeMD, you can speak with a licensed healthcare provider about how to stay safe with a fish allergy. 

They can give tips to help you stay safe during an allergic reaction and know what foods to watch out for that you may not expect.

Book an appointment today to learn more about managing a fish allergy.

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