About Shellfish Allergy
A shellfish allergy is not exactly the same as a seafood allergy. Seafood
includes fish (like tuna or cod)
and shellfish (like lobster or clams). Even though they both fall into the
category of "seafood," fish and shellfish are biologically different.
So fish will
not cause an allergic reaction in someone with a shellfish allergy, unless
that person also has a
Shellfishfall into two different groups:crustaceans(like shrimp, crab, or lobster) and mollusks(like clams, mussels, oysters, scallops, octopus, or squid). Some people
with shellfish allergies are allergic to both groups, but some might be
allergic only to one.
Most allergic reactions to shellfish happen when someone eats shellfish,
but sometimes a person can react to touching shellfish or breathing in
vapors from cooking shellfish.
Shellfish allergy can develop at any age. Even people who have eaten shellfish
in the past can develop an allergy. Some people outgrow certain
food allergies over time, but those with shellfish allergies usually have the allergy
for the rest of their lives.
A shellfish allergy can cause a very serious reaction, known as
anaphylaxis, even if a previous reaction was mild. So anyone with a shellfish allergy
should completely avoid shellfish.
If your child has been diagnosed with a shellfish allergy, keep injectable
epinephrine on hand in case of a severe reaction. This is a medicine that
your doctor can prescribe. Discuss
emergency plans with anyone who will be taking care of your child, including relatives
and school officials. Also consider having your child wear a medical alert bracelet.
What Happens in a Shellfish Allergy
When someone is allergic to shellfish, the body's
immune system, which normally fights infections, overreacts to proteins in the shellfish.
Every time the person eats (or, in some cases, handles or breathes in)
shellfish, the body thinks these proteins are harmful invaders.
The immune system responds by working very hard to fight off the invader.
This causes an allergic reaction, in which chemicals like histamine are
released in the body. The release of these chemicals can cause someone
to have these symptoms:
- trouble breathing
- throat tightness
- itchy, watery, or swollen eyes
- red spots
a drop in
blood pressure causing lightheadedness or loss of consciousness
Your child could have different reactions to different types of shellfish
or react differently at different times. Some reactions can be very mild
and involve only one system of the body, like
hives on the skin. Other reactions can be more severe and involve more than
one part of the body.
Anaphylaxis Is a Life-Threatening Reaction
Shellfish allergies can cause a severe reaction called anaphylaxis. Anaphylaxis
can begin with some of the same symptoms as a less severe reaction, but
then can quickly worsen, leading someone to have trouble breathing or
to pass out. If it is not treated, anaphylaxis can be life-threatening.
If your child starts having serious allergic symptoms, like swelling of
the mouth or throat or difficulty breathing, give the epinephrine auto-injector
right away. Every second counts in an allergic reaction. Then call 911
or take your child to the emergency room. Your child needs to be under
medical supervision because even if the worst seems to have passed, a
second wave of serious symptoms may follow.
An epinephrine auto-injector is a prescription medicine that comes in an
easy-to-carry container about the size of a large marker. It's simple
to use. If your child needs to have it on hand, your doctor will show
you how to use it. Kids who are old enough can be taught how to give themselves
Staff at your child's school should know that your son or daughter
has a serious food allergy. You should agree upon a plan in case of a
serious reaction and be sure that the injectable epinephrine is available
at all times. If your child is old enough to carry the epinephrine, it
should not be in a locker, but in a purse or backpack that's with
your child at all times.
Your child's allergy plan also might include giving an over-the-counter
antihistamine for milder allergy symptoms. But the antihistamine should be given
after the epinephrine in the case of a serious, life-threatening reaction.
Shellfish Allergy Safety Tips
To prevent allergic reactions, your child must not eat shellfish. He or
she also must not eat any foods that might contain shellfish as ingredients.
For detailed information, visit food allergy websites, such as the
Food Allergy Research and Education (FARE), or others that your doctor recommends.
food labels to see if a food is free of shellfish. Makers of foods sold in the United
States must state in understandable language whether foods contain any
of the top eight most common allergens, including crustacean shellfish.
The label should list "shellfish" in the ingredient list or
say "Contains shellfish" after the list.
Also look for advisory statements such as "May contain shellfish,"
"Processed in a facility that also processes shellfish," or
"Manufactured on equipment also used for shellfish." These are
cross-contamination warnings, but manufacturers are not required to list them.
Because products without precautionary statements also might be cross-contaminated
and the company simply chose not to label for it, it is always best to
contact the company to see if the product could contain shellfish. You
might find this information on the company's website or you can email
a company representative.
Manufacturers also do not have to list mollusk shellfish ingredients because
mollusk shellfish (clams, mussels, oysters, or scallops) are not considered
a major food allergen. When labels say a food contains shellfish, they
refer to crustacean shellfish. Contact the company to see about cross-contamination
risk with mollusks.
Even if a food did not cause a reaction in the past, it still could be
a problem. Manufacturers may change processes or ingredients at any time.
Shellfish ingredients also might be used in some non-food products, like
nutritional supplements, lip gloss, pet foods, and plant fertilizer. Talk
to your doctor if you have questions about what is safe.
Cross-contamination is common in restaurants, which is where many people
often mistakenly eat shellfish. This happens in kitchens when shellfish
gets into a food product because the staff use the same surfaces, utensils
(like knives, cutting boards, or pans), or oil to prepare both shellfish
and other foods.
This is particularly common in seafood restaurants, so some people find
it safer to simply avoid these restaurants altogether. Since shellfish
is also used in a lot of Asian cooking, there's a risk of cross-contamination
in Chinese, Vietnamese, Thai, or Japanese restaurants. It's a good
idea to avoid a restaurant's fried foods, like French fries and fried
chicken, because the restaurant may use the same oil to fry shrimp.
Eating Away From Home
When your child eats in a restaurant or at a friend's house, find out
how foods are cooked and exactly what's in them. It can be hard to
ask a lot of questions about cooking methods, and to trust the information
you get. If you can't be certain that a food is shellfish-free, it's
best to bring safe food from home.
Also talk to the staff at school about cross-contamination risks for foods
in the cafeteria. It may be best to pack lunches at home so you can control
what's in them.
If your child will be eating at a restaurant, take these precautions:
- Stay away from steam tables or stovetops when shellfish is cooked (especially
places where food is cooked on a communal grill, like hibachi restaurants).
- Tell the restaurant waitstaff that your child has as serious shellfish allergy.
- Carry a personalized "chef card" for your child, which can be
given to the kitchen staff. The card details your child's allergies
for food handlers. Food allergy websites provide printable chef card forms
in many different languages.
- Don't eat at a restaurant if the manager or owner seems uncomfortable
about your requests for a safe meal.