January 21, 2018

What Is a Shellfish Allergy, and How to Live with It?

Most people with food allergies develop their first symptoms in childhood, but allergies to fish and shellfish tend to occur later in a person’s life. According to research, estimated 6.5 million American adults have fish allergy or shellfish allergy, or both.


Shellfish allergy usually begins in adulthood, and it can be triggered by foods that didn’t cause any problems before.

What Can Trigger Your Allergy to Shellfish?


Shellfish in general can be divided into two categories: crustaceans and mollusks. Crustaceans include shrimps, lobsters, crayfish, crabs and prawns, whereas the term “mollusks” covers mussels, oysters, octopus, squids, clams, cuttlefish, snails and scallops.

Both types of shellfish may trigger an allergic reaction. Besides, if you are allergic to crustaceans, you are likely to be allergic to mollusks as well. Experts recommend people with allergies to shellfish to avoid all kinds of it, for safety reasons. However, some people may still be able to eat certain varieties without getting a reaction.

There are also a few more factors that make a shellfish allergy different from others. Thus, it’s almost impossible to predict an allergic reaction to shellfish. You may consume the allergen and feel absolutely fine afterwards, while the symptoms may occur much later. In addition, the more you expose yourself to the allergens, the more severe your allergic reactions are.

What Are the Symptoms of Shellfish Allergy?


An allergic reaction to shellfish is usually triggered by a protein tropomyosin, that is found in shellfish muscles. When tropomyosin gets into your system, your immune system mistakenly perceives it as a dangerous substance and releases special chemicals called histamines to protect you. These chemicals are responsible for the symptoms you are suffering from. The symptoms of shellfish allergy can vary from mild to life-threatening, but in most cases, they tend to be rather severe.

As it mentioned earlier, these symptoms may occur long after you eaten shellfish. However, most people experience them within a few minutes.

If you are allergic to shellfish, eating it may cause such symptoms as tingling in the mouth, congestion, difficulty breathing, abdominal pain, nausea, vomiting, diarrhea, itching of the skin, jives, eczema, swollen face, lips, tongue, throat, ears, fingers or hands, as well as dizziness and fainting.

In some people, shellfish may trigger an anaphylactic reaction. Anaphylaxis is a serious, life-threatening allergic reaction that cause swelling of the throat (or lamp in the throat), difficulty breathing, a severe drop in blood pressure, rapid pulse, and dizziness or fainting. If you or someone around you is having an anaphylactic reaction, you should seek for medical help immediately.

How Can You Treat Shellfish Allergies?


Allergy to shellfish is an incurable condition, and the best way to prevent the symptoms is to avoid the trigger foods including shrimps, lobsters, oysters, etc. When it comes to finned fish, they normally don’t trigger allergies, but they can be easily cross-contaminated. Therefore, experts often recommend that people with severe shellfish allergies avoid all kinds of seafood.

Another common recommendation in this case is to carry epinephrine (adrenaline) gadgets like EpiPen, Adrenaclick or Auvi-Q in case of emergency. Epinephrine injection is the first aid for people having an anaphylaxis attack. Although anaphylactic reactions triggered by shellfish rarely lead to fatal consequences, deaths caused by food allergies are more common with shellfish, than with other foods.

If you have a shellfish allergy and asthma, doctors suggest that you always carry an epinephrine injection with you, for safety reasons.

When the symptoms you have because of shellfish are not severe (for example, when you have a rash or itchy skin), you can control them with antihistamine medications like Benadryl. In case your symptoms don’t improve, you will need to seek for medical help.

How to Diagnose a Shellfish Allergy?


In order to see whether you are allergic to shellfish or not, you need to undergo a skin prick test. This is a simple procedure that involves inserting a small amount of the allergen into the skin of the forearm. If you are allergic, your immune system will intent to protect your body by releasing a chemical histamine. As a result, a small itchy red bump will appear on the spot on your forearm after a few minutes. If you don’t seem to develop any symptoms during this time, the chances that you have the allergy are low.

Shellfish allergies can also be diagnosed using a blood test known as an allergen-specific IgE antibody test or radioallergosorbent (RAST) test. This test works by measuring the immune system’s response to shellfish.

A shellfish allergy cannot be diagnosed without any allergy testing, even if your symptoms seem to be allergic.

Is It Possible to Prevent Shellfish Allergies?


There is no way to prevent a shellfish allergy except avoiding all foods that contain or might contain shellfish. Below, you will find some tips to help you.

First, you should try to avoid eating at seafood restaurants. The same applies to shopping in fish markets. This is because the reaction may be caused even by steam or vapor coming from cooking shellfish. Besides, cross-contamination is common in places serving seafood.

When eating out, you should always ask the waiter how your meal is prepared. You can ask that your food is prepared using utensils that didn’t touch shellfish. You should also stay away from steam buffets, and pay attention to sauces served at Asian restaurant, since some of them may contain fish or shellfish flavors.

Reading food labels is one of the basic things you can do to minimize your exposure to the allergens. Normally, companies must disclose the ingredients of their food products. However, in some cases, mollusks such as oysters or scallops may be stated in the list under some vague terms like “seafood flavoring” or “fish stock”.

In addition, shellfish may often be found in surimi, Bouillabaisse, Caesar salads, Worcestershire sauce and glucosamine.

It is important that you inform people about your allergy. For instance, when you are flying, you have to ask the airline whether any shellfish dishes will be served on board. When you are invited to a dinner party, tell the host about your sensitivity. If your child is allergic to shellfish, you must inform his or her school about it.

Make sure to always carry a valid epinephrine pen with you, in case of an emergency. People with severe allergies should also wear a special medical bracelet or necklace that contains the information about their condition.

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