In the United States, about 2% of the general population is reported to suffer from a shellfish allergy. Here are three things parents need to know about shellfish allergies.
What are the signs of shellfish allergies?
If your child has a shellfish allergy, they may experience a variety of symptoms after eating a food that contains shellfish. These symptoms can take up to an hour to appear.
Your child may tell you that the inside of their mouth feels tingly or that their tongue and lips feel swollen. They may tell you that they feel dizzy or lightheaded, and they may even faint. The tissues around their mouth, like their lips or tongue, may also become swollen. This swelling can constrict their airway and make it hard—or impossible—to breathe, so prompt medical attention is very important.
How are shellfish allergies diagnosed?
There are two main tests that are used to diagnose shellfish allergies, and your child may need to undergo one or both of them. These tests are skin tests and blood tests.
Skin tests involve pricking your child's skin and exposing them to small amounts of shellfish proteins. Their allergist will then monitor your child for about 15 minutes to see if their immune system reacts. If an itchy, raised bump (known as a hive) forms at the site of the skin prick, your child may have a shellfish allergy.
Blood tests look for immunoglobin E (IgE) antibodies in the blood. These antibodies are present when the body's immune system has responded to shellfish proteins. Since the blood needs to be drawn and then sent to a laboratory for analysis, you won't get the results for a few days.
What foods contain shellfish?
Lobsters, crabs, clams and shrimp are obvious foods to avoid, but many foods contain hidden sources of shellfish. Ethnic foods like fried rice or spring rolls could contain shellfish and should be avoided. Salad dressings and sauces—like steak sauce or marinara—can also contain shellfish. Even deli meats and hot dogs can contain shellfish!
Any food that comes from a deep fryer should also be treated with caution; restaurants may cook their fries and onion rings in the same oil as they cook their breaded shrimp! If you take your child to a restaurant, be sure to mention their allergy.
If you're concerned that your child has a shellfish allergy, take them to an allergist, like Asthma and Allergy Clinic, for testing.