Seafood (fish and shellfish) allergy factsheet

Introduction

Allergic reactions to seafood (fish and shellfish) are common. They can develop at any age but are seen more in older children and teenagers.

Many types of fish and shellfish can cause allergic reactions.

They are generally split into

Vertebrates - fish with a backbone

For example:

salmon
barramundi
cod
tuna
sardines
eels
rays.

Invertebrates - sea creatures with and without shells, but no backbone

For example:

crabs
lobsters
prawns
yabbies
oysters
mussels
octopus
squid, also known as calamari
abalone
snails, also known as escargot
edible crickets.

Some children are allergic to one or both categories. Other children may be allergic to specific animals in each group.

For example, your child may be allergic to salmon but can eat prawns without issues.

Seafood allergy is usually life-long. Only around 20% of children will grow out of their allergy.

Like any other allergy, it is important to talk to your child’s doctor before reintroducing foods that have previously caused an allergic reaction.

Signs and symptoms

Allergic reaction to seafood can be triggered by:

eating or touching seafood
breathing in fumes or steam where seafood is being cooked
eating or touching food or items that have touched seafood
touching other products that contain seafood, like pet food.

Allergic reactions are usually fast and happen within minutes of exposure to seafood.

Reactions can include:

hives or welts on the skin
redness of the skin
vomiting and stomach ache
tingling and swelling of the mouth, lips, face, and eyes.

Some children can have a more severe allergic reaction called anaphylaxis.

Signs of anaphylaxis include:

wheezing, difficult, or noisy breathing
swelling of the tongue
swelling or tightness in the throat
a persistent cough
difficulty talking or a hoarse voice
dizziness
becoming pale and floppy in young children
collapsing.

If your child has signs of anaphylaxis, you should:

follow your child’s ASCIA action plan for anaphylaxis if you have one
use an EpiPen or Anapen, if available
call Triple Zero (000) for an ambulance.

Some children can develop a delayed reaction that takes hours or days.

Symptoms of a delayed reaction can include:

vomiting and nausea
abdominal pain or stomach ache
bloating
diarrhoea.

See your local doctor as soon as possible if your child is showing signs of an allergic reaction for the first time.

Symptoms of mild allergic reactions should fade over time. See your local doctor as soon as possible if symptoms do not get better or you are concerned.

Diagnosis

If you think your child has had an allergic reaction that is not anaphylaxis, write down the following and see your local doctor as soon as possible:

time of seafood exposure
what type of seafood it was
time of reaction
type of reaction
amount of seafood your child ate or was exposed to
type of exposure –touching, eating or breathing in fumes.

A specialist doctor can diagnose a seafood allergy based on your child’s:

medical history
signs and symptoms
results from allergy tests.

Some children will grow out of their seafood allergy.

A food challenge can be done to figure out whether your child has grown out of their allergy and whether seafood can be reintroduced to their diet safely. Food challenges are done under the supervision of a doctor in the hospital.

Treatment

Your child's doctor will find the best possible treatment for their allergy based on their individual health needs. In most cases, your child must carefully avoid seafood in their diet.

Children at risk of anaphylaxis need:

an ASCIA action plan
an adrenaline injector, also known as an EpiPen® or Anapen.

Your child will also need to learn how to identify foods that contain seafood as they get older and become more independent with their diet.

Management

Common sources of seafood

Seafood is a common ingredient in food dishes like noodle soups, curry, stir-fries, and rice, and it can be difficult to avoid.

Some foods will visibly include seafood, such as sushi, calamari, or fish cakes.

Seafood can also be found in other foods and products like:

sauces, broths, and stocks - for example, oyster and fish sauce, dashi, Worcestershire sauce
spreads, dips, and salad dressings
cooking oil when previously used to cook seafood, for example, in a deep fryer
pet food
supplements like fish and krill oil.

It is important for your family and your child to learn about which foods and products contain their seafood allergen and what seafood group they are allergic to.

Seafood, food labels and eating out

It is important to always check the package and ingredient list of all foods your child eats.

In Australia, allergens are shown in bold each time they appear in an ingredient list. Packaged foods may have a warning on the label that "may contain traces of fish/shellfish".

This means the food is made in a facility that also makes foods that contain certain types of seafood.

Talk to your child’s doctor about whether these foods are safe.

Tell staff about your child’s specific seafood allergy to avoid exposure when eating out.

If you cannot confirm that a food does not contain or has not touched your child’s specific seafood allergen, it is safest for your child to avoid it.

Education

The most important thing you can do is support your child in avoiding their seafood allergen. You can also educate your child, family, and friends about allergies, reactions, and what to do in an emergency.

Parents of younger children will need to read ingredient lists and learn to find their seafood allergen in foods and drinks.

Older children can be supported in learning to read ingredient lists and find their seafood allergen in foods and drinks.

This can help keep children safe and encourage them to be more independent and confident about their diet and health as they grow.