Shellfish Allergy: A Complete Guide

Living with a food allergy is frustrating and even limiting at the best of times, but there are certain food allergies that are downright dangerous. One of those is a shellfish allergy.

This is the type of allergy that’s usually first identified in childhood, but certain shellfish intolerances can develop with age. Contrary to what many first-time parents believe, it’s actually wise to expose your child to certain food allergens from an early age. This is the only way you can determine whether they have food allergies and their severity.

Interested in learning more about the causes, symptoms, and treatment for a shellfish allergy? This is the guide you need.

The Definition of a Shellfish Allergy

As you may have already guessed, this is a type of food allergy that causes a range of unpleasant symptoms when you consume all or certain forms of shellfish.

What are the different types of shellfish, anyway? By definition, these are animals with a shell-like exterior, and they tend to live in water (mostly saltwater):

  • Mollusks include scallops, oysters, clams, squid, and mussels
  • Crustaceans include crab, lobster, shrimp, prawns, and crayfish

Just like any other food allergy, it can range in severity. For example, you may only have an adverse reaction to certain types of shellfish, but not all. Your reaction might only include an itchy nose or hives, or be as severe as anaphylactic shock.

Shellfish Allergy Symptoms, Causes, and Treatment

Once an individual eats shellfish, an allergic reaction can set in within two minutes, or up to an hour later. When feeding your child shellfish, you need to keep a close eye on them for the full hour to gauge whether a reaction sets in.

So, what are the symptoms to look out for?

  • Itching of the skin, eczema, or a rash of hives
  • Swelling — this can happen in the face, tongue, lips, throat, hands, and other body parts
  • Trouble breathing, i.e. nasal congestion or wheezing
  • Vomiting, nausea, diarrhea, or stomach cramps/pain
  • Fainting, dizziness, or lightheadedness

These are some of the milder symptoms when having an allergic reaction to shellfish. Of course, there’s also the risk of more severe reactions, such as anaphylaxis. Because this is a life-threatening reaction, it’s vital that you know how to recognize symptoms of anaphylaxis:

  • Swelling of the throat, or an obstruction in the throat that causes labored breathing
  • Shock, often characterized by a sudden drop in blood pressure and pale skin
  • Rapid heart rate
  • A loss of consciousness or severe dizziness

Anaphylactic shock is a serious condition that you should treat as a medical emergency. The treatment for anaphylaxis is a shot of epinephrine (adrenaline), via injection. Call 911 or visit the emergency room as soon as symptoms arise, don’t wait to see if they get better!

What Causes a Shellfish Allergy?

Any type of food allergy is usually the result of an overreaction by the immune system.

The immune system mistakenly recognizes certain elements within food as harmful. The result is a huge influx of antibodies into the bloodstream to try and counter what the body perceives as an ”attack”. The immune system releases a natural hormone known as histamine, which serves this very purpose. The result is a slew of unwanted side effects as mentioned above.

In the case of shellfish, the immune system overreacts to a specific type of protein in the shellfish — known as an allergen. It’s worth noting that some people might only have an allergy to certain types of shellfish, while others can’t tolerate any shellfish at all.

This is where skin prick tests come in handy to decipher what you can and cannot tolerate. Some people might also struggle with an intolerance to shellfish which only results in mild reactions. An allergy, on the other hand, is always far more serious.

Risk Factors for a Shellfish Allergy

Who’s more likely to develop a shellfish allergy? There is actually no definitive answer to this because food allergies are very individualized conditions. Almost anyone could develop an allergy, even if you were able to consume shellfish before without any adverse reactions.

This means that a shellfish allergy can set in at any age, but it’s worth noting that it’s far more common in adults than in children. Shellfish allergies impact up to 2.3 percent of the population in the United States, making it one of the more common food allergies out there.

You are far more likely to develop a shellfish allergy in your lifetime if you have family members that struggle with food allergies of any kind. If you live with conditions such as asthma, this can also put you at greater risk of anaphylaxis when allergic to shellfish.

What Does Treatment Look Like?

If you suspect that you or your child might have a shellfish allergy, it’s best to seek out an official diagnosis from a medical professional. They will most likely carry out a range of skin prick tests to assess your tolerance levels.

Once they’ve identified your allergy, it’s super important to take note of what you’re eating — specifically the ingredients in what you’re eating. It might sound tedious, but you’ll have to check the ingredient list of certain food items to ensure they’re free from allergens. This is especially important if you or your child has a more severe shellfish allergy.

When dining out, you’ll also need to take extra precautions. Make sure to ask about the ingredients in certain dishes if you’re unsure of what’s in them. If the wait staff cannot tell you, ask them to find out and let them know about your allergy, too.

Bear in mind that shellfish is a fairly obvious ingredient. In other words, you can’t easily hide it in other foods, like other allergens such as nuts, gluten, soy, or cow’s milk protein.

Crustacean shellfish also falls under the 8 allergen labeling requirements by the Food Allergen Labeling and Consumer Protection Act of 2004. This means that it should always appear on a list of ingredients, by law.

If you have a mild allergic reaction when consuming something this might include hives, itching, and watering eyes. The best way to treat these symptoms is with antihistamines. This is a type of medication your doctor will prescribe or recommend for you.

If you have a more severe allergy and experience symptoms of anaphylactic shock, your doctor will prescribe you an EpiPen. This is an auto-injectable device that includes a shot of epinephrine (adrenaline).

Always take note of the expiration date on your EpiPen and ask your doctor about repeat prescription renewals.

Find Food Freedom, With Us

If your child was recently diagnosed with a shellfish allergy or any food allergy for that matter, we’re here to help you and them find the food freedom they deserve.

Learn more about our Tolerance Induction Program, known as TIP, and how we can help!