What is a fish allergy?
A fish allergy is a reaction to one or more of the proteins in fish.
It can be easy to mistake a true fish allergy for histamine poisoning. Anchovies, mackerel, mahi-mahi and tuna can contain high levels of histamine when they are not properly frozen or refrigerated. When someone eats these improperly stored fish, they may experience similar symptoms to that of a fish or seafood allergy. See your child's doctor if you suspect your child has histamine poisoning.
How serious is a fish allergy?
Fish allergy reactions are different for each child, but they usually happen soon after your child consumes fish. A fish allergy carries the risk anaphylaxis, a severe and life-threatening allergic reaction.
Fish and seafood allergies
Not all children who have a seafood allergy will have a fish allergy. However, all children who have a fish allergy are considered to have a seafood allergy, as fish is a type of seafood.
Other names for fish
Fish can have many names in ingredient lists. Learning these names can help you catch any hidden sources of fish in food.
When buying packaged foods, always check the list of ingredients in the store and again when you bring the product home. It is also a good idea to check the ingredients every time you buy the food in case the recipe has changed. You can also call the manufacturer to ask about any recipe changes.
The following table lists some names for fish. Use it when you are grocery shopping or calling food manufacturers.
| Anchovy | Bass |
| Cap | Catfish |
| Char | Cod |
| Eel | Halibut |
| Herring | Mackerel |
| Mahi-mahi | Marlin |
| Orange roughy | Pickerel (walleye) |
| Pike | Pollock |
| Salmon | Sardine |
| Snapper | Trout |
| Tuna (albacore, yellow fin, bonito) | White fish |
Possible sources of fish
Fish and other seafood are used in a wide range of packaged foods. Below is a list of some of the many food products that can contain fish.
| Coffee | Deli meats (bologna, ham) |
| Fried rice | Gelatin |
| Hot dogs | Marshmallows |
| Salad dressing (for example Caesar dressing) | Soups and sauces |
| Spring rolls | Sushi |
| Worcestershire sauce |
What do I do if my child has a fish allergy?
Your child should see an allergist (a doctor who specializes in diagnosing and treating allergies) who can discuss the fish allergy with you in more detail. Children who have a fish allergy may need to avoid all products that may contain fish.
Your child’s doctor will also prescribe a medication called an epinephrine auto-injector, which can be used to treat allergic reactions, in case your child accidentally eats a food containing fish.
If my child has an allergy to fish, must they avoid all seafood?
Some people may be allergic to one group of seafood, such as fish, but may be able to eat other groups of seafood, such as molluscs or crustaceans, as long as one group has not come in contact with the other in any way.
In addition, allergic reactions do not always occur within complete families of seafood. For example, a person can be allergic to salmon but not to other types of fish.
If your child has an allergy to a specific fish, speak to an allergist before letting them try other types of fish or seafood. Your child may need to avoid all seafood due to the high chance of cross-contamination (see below), as fish products are often processed in the same facility as other seafood products.
Reducing the risk of cross-contamination
Cross-contamination occurs when one substance unintentionally comes in contact with another substance, for example a potential allergen. If the substances mix together, the one substance taints the other substance, making it unsafe to eat.
Food allergens can contaminate other foods when, for example, the same food containers, utensils or frying pans hold a range of foods.
Avoid using utensils or containers that may have come in contact with allergy-causing foods and ask about possible cross-contamination when eating out.
How can my child get the right mix of nutrients if they must avoid fish?
The main nutrients in fish include protein, omega-3 fats, vitamin A, vitamin B12, vitamin D, vitamin E, calcium, iron and zinc. Your child can still get these nutrients even if they must avoid fish and products that contain them.
Nutrients in fish that are found in other foods
| Nutrient | Where to find it |
|---|---|
| Protein | Milk, chicken, egg, beans, soy |
| Omega-3 fats | Flaxseed oil, edamame (soybeans), radish seeds, omega-3 eggs fortified with DHA |
| Vitamin A | Sweet potato, pumpkin, liver, goat cheese, carrots, squash, spinach |
| Vitamin B12 | Milk, cheese, liver, beef |
| Vitamin D | Milk or soy beverage fortified with vitamin D |
| Vitamin E | Spinach, red pepper, Swiss chard, wheat germ cereal, egg, almonds, sunflower seeds |
| Calcium | Milk, buttermilk, cheese, yogurt, spinach, collards, beans, soy beverage fortified with calcium |
| Iron | Spinach, tomato puree, edamame, lima beans, snow peas, instant oatmeal, cereal |
| Zinc | Bran cereal, wheat germ, cheese, milk, beef, pumpkin seeds, baked beans |
Can my child with a fish allergy enjoy sushi?
Many kinds of delicious sushi rolls do not contain any fish. If you dine at a sushi restaurant, contact the restaurant ahead of time to tell them about your child’s allergy. Ask if the restaurant can provide fish-free sushi that is not contaminated by sushi rolls that contain fish.
When to see a dietitian about a fish allergy
If you have removed many foods from your child's diet because of a fish allergy, it may be a good idea to speak to a registered dietitian. The dietitian can review the foods your child still eats to decide if they are getting enough nutrients. If necessary, they can also recommend alternative foods that your child can eat safely.
Will my child always have a fish allergy?
Most children with a fish allergy will continue to have it as they get older. An allergist can help you find out when to test your child and see whether they have outgrown their allergy.
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When to go the emergency room
If your child is having a severe allergic reaction to fish, call 911 or go to your nearest emergency department immediately. If your child’s doctor prescribed them an epinephrine auto-injector, administer this medication to your child right away. See Anaphylaxis: How to recognize and respond to a severe allergic reaction for more information.
Further information
Health Canada. Seafood (fish, crustaceans and shellfish) - One of the ten priority food allergens