How Bad Are Fish and Shellfish Allergies?

million Americans are allergic to seafood

Fish and shellfish (specifically crustacean) are one of the eight most allergenic foods known to cause severe allergy attacks. Unlike some other food allergies, an allergy to finned fish and/or shellfish is usually lifelong.

An allergy to shellfish is one of the more common and also one of the most dangerous food allergies. Making matters worse, a shellfish (and fish) allergy can develop at any time during a person’s life. According to Food Allergy Research & Education, fish and shellfish allergies are the most common adult-onset food allergies.

There are more than 20,000 species of fish, but salmon, tuna, and halibut top the list of the kinds of fish most people are allergic to. And shellfish can be divided into two groups: crustacean shellfish (cause the most reactions) such as shrimp, crab, lobster; and molluscan shellfish such as clams, mussels, oysters, octopus, squid, and scallops.

Most Common Fish & Shellfish Allergies

  • Anchovies
  • Bass
  • Catfish
  • Cod
  • Flounder
  • Grouper
  • Haddock
  • Hake
  • Halibut
  • Herring
  • Mahi mahi
  • Perch
  • Pike
  • Pollock
  • Salmon
  • Scrod
  • Sole
  • Snapper
  • Swordfish
  • Tilapia
  • Trout
  • Tuna
  • Shrimp
  • Crab
  • Lobster
  • Clams
  • Mussels
  • Oysters
  • Octopus
  • Squid
  • Scallops

A fish and shellfish allergy is a type of immune response triggered by ingesting one or more of the varieties of fish and/or shellfish. The immune system normally reacts to al-lergens by protecting us from any kind of a negative response. However, the immune response of an individual with a food allergy is oversensitive. When faced with an al-lergen, the system reacts by releasing substances that cause allergy symptoms.

Because there appears to be no relationship between fish and shellfish allergies, people with a fish allergy do not necessarily have to avoid shellfish (and vice versa). Even the smallest amount of fish or shellfish that a person is allergic to can cause a reaction, so it’s important to know how to avoid exposure to these food items and be able to spot the symptoms of an allergic reaction if fish or shellfish are ingested.

Seafood Allergy Symptoms

The most common cause of an allergic reaction to fish or shellfish is direct contact through food. People with a fish or shellfish allergy may experience an allergic reaction anywhere from a few minutes to a few hours or longer after consuming the allergen. Allergic reactions to shellfish are unpredictable, and in some cases, can happen long after a person has consumed the allergen.

Most Common Symptoms of Fish/Shellfish Allergies

  • Flushing and swelling of the face, mouth, lips, tongue, throat, ears, fingers, or hands
  • Tingling in the mouth
  • Wheezing, trouble breathing, coughing, tight throat
  • Digestive issues such as nausea, vomiting, and diarrhea
  • Itching and hives
  • Itchy, watery, or swollen eyes
  • Sudden drop in blood pressure with causes lightheadedness or loss of consciousness, and a rapid heartbeat

In severe cases, an allergy to fish or shellfish can also result in anaphylaxis, a sudden, severe, and life-threatening allergic reaction that can involve several areas of the body. If you have a fish and/or shellfish allergy, it is recommended to keep an epinephrine auto-injector with you at all times. An epinephrine injection is the only treatment for anaphylaxis.

There are several steps involved in testing for and diagnosing an egg allergy. Consult your allergist or physician for further information.

Avoiding Exposure to Fish & Shellfish Products

Even trace amounts of a food allergen can cause a reaction. Since there is such a high level of cross-contact within the food groups, your health care provider may advise you to avoid fish or shellfish in all forms. However, if you happen to be someone who is allergic to just one or two forms of fish or shellfish, consult with your doctor or allergist about the safety of eating other forms of fish or shellfish.

The best way to manage a fish or shellfish allergy is to read the labels and avoid any food that is a potential allergen including:

  • Fish such as tuna, salmon, and halibut
  • Shellfish such as shrimp, crab, prawn, crawfish, lobster, clams, mussels oysters, squid, cuttlefish, octopus, snails, and scallops

Make sure to look for these terms (related to fish or shellfish) when reading labels. Eating any one of the following products or ingredients can potentially lead to an allergic reaction:

  • Surimi
  • Glucosamine
  • Bouillabaisse
  • Worcestershire sauce
  • Caesar salad and dressing
  • Caponata
  • Barbecue sauces made with Worcestershire
  • Caviar and fish roe
  • Fish sauces, oils, and gelatin
  • Asian cuisines

Special Seafood Considerations

Cross-contact is a serious issue facing individuals with a food allergy. Cross-contact can happen when a food is exposed to fish or shellfish during processing or handling. For example, a kitchen tool (i.e., a knife) that was previously used to cut the tails off of shrimp is now being used to slice potatoes. Even though potatoes do not contain shellfish products, the knife (with shrimp on it) has now introduced the allergen into the food.

Regulations Related to Fish & Shellfish Allergies

The U.S. Food and Drug Administration (FDA) is primarily responsible for enforcing the Food Allergen Labeling and Consumer Protection Act of 2004, which requires that food labels clearly identify the food source names of any ingredients that are one of the major food allergens (including fish and shellfish) or contain any protein derived from a major food allergen.

The law further explains that the name of the food source of a major food allergen must appear in parentheses following the name of the ingredient or next to the list of ingre-dients in a “contains” statement.

Unfortunately, the FALCPA’s labeling requirement does not apply to products that may be contaminated due to cross-contact. The FDA does not regulate statements such as: “may contain shellfish,” or “manufactured on shared equipment with shellfish” or “manufactured in the same facility as shellfish” so there is no guarantee that products labeled as such are safe.

It’s important to note that fish and the crustacean shellfish (i.e., shrimp, crab, and lobster) are part of the labeling requirements. But shellfish that are part of the molluscan family, like scallops and oysters, are not required to be identified on a label.