Shellfish allergy symptoms, remedies, & alternatives

It’s true that with food allergies, one person’s food can truly be another one’s poison. The popularity of shellfish has been on the rise worldwide, but as a result, shellfish are the leading cause of food allergies in American adults. The approximate prevalence of shellfish allergy is estimated to be between 0.5 percent and 2.5 percent of the general population.

A shellfish allergy can be a life-threatening condition, so it’s crucial that people are educated about shellfish allergy symptoms, the less obvious foods that may contain shellfish, and natural remedies that can help reduce the body’s immune response.

What Is a Shellfish Allergy?

“Shellfish” and “seafood” are often used interchangeably but with different meanings. According to research published in Clinical and Translational Allergy, “seafood” is a general term that refers to any edible aquatic animal, while “shellfish” specifically refers to those with a shell or shell-like exoskeleton.

There are several known groups and subgroups of shellfish species. One type is crustaceans, which in Latin means “having a crust or shell.” Crustaceans belong to the arthropoda category, which all have hard exoskeletons or shells, segmented bodies, and jointed limbs. There are over 50,000 known species of crustaceans. Some well-known crustaceans include crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, and barnacles.

The mollusca is the largest marine phylum, comprising about 23 percent of all the named marine organisms. Cephalopod molluscs like squid, cuttlefish, and octopus are among the most neurologically advanced mollusca. Giant squid are the largest, and gastropods like snails and slugs are by far the most numerous, making up 80 percent of all mollusca. Other molluscs include scallops, clams, mussels, oysters, and other bivalves.

Allergies to crustacean shellfish are more common, while molluscan shellfish allergies are well known but not as frequent. The major shellfish allergen has been identified as tropomyosin, a muscle protein that is present in different species of shellfish and may be responsible for cross-reactivity. This is why most people who are allergic to one type of shellfish are often allergic to others as well. Shellfish is one of the leading causes of food allergies in adults and a common cause of food-induced anaphylaxis. In the U.S., a survey involving 14,948 individuals revealed that 2 percent to 3 percent of people believe they have seafood allergies: 2.2 percent to shellfish and 0.6 percent to fish. From highest to lowest prevalence, shellfish allergy is most common in shrimp, crab, lobster, clam, oyster, and mussels.

The growing international trade of seafood has increased the popularity of various seafood products across the country. The increased production and consumption have been accompanied by more frequent reports of adverse health problems among consumers and processors of seafood. Research shows that adverse reactions to seafood are often caused by contaminants but can also be mediated by the immune system and lead to allergies.

Symptoms

Shellfish allergy symptoms are mediated by antibodies produced by the immune system in response to specific allergens. These antibodies trigger the release of chemicals (such as histamines) to attack the protein that causes the immune response. Non-immunological reactions to seafood can be triggered by contaminants like parasites, bacteria, viruses, marine toxins, and biogenic amines. Ingredients added during processing and canning of seafood can also cause adverse reactions. All of these substances can mimic the symptoms of true shellfish allergy.

Although the severity of shellfish allergy symptoms can vary widely, they tend to be more intense than most other food allergens and are unpredictable, sometimes occurring long after a person has consumed the allergen. Symptoms of shellfish allergy can range from mild hives and itching to life-threatening anaphylaxis. Most reactions are IgE-mediated and involve the rapid onset of gastrointestinal, cutaneous (affecting the skin), or respiratory issues. Common shellfish allergy symptoms include: itchy skin, hives, eczema; swelling of the face, lips, tongue, throat, ears, fingers, or hands; congestion; trouble breathing or wheezing; tingling in the mouth; abdominal pain; nausea or vomiting; diarrhea; dizziness; and fainting. When a large amount of chemicals cause shock, it is called an anaphylactic reaction. Anaphylaxis can occur suddenly and progress quickly. The early signs of anaphylaxis may be mild, such as a skin rash or a “strange feeling,” but it can lead to more serious problems like trouble breathing, hives or swelling, tightness of the throat, nausea, vomiting, abdominal pain, dizziness, and fainting, a drop in blood pressure, a rapid heart rate, and even cardiac arrest. People who have had a severe allergic reaction to shellfish are at a higher risk for future reactions and should carry a self-injectable epinephrine. There is a misconception that people with a shellfish allergy are more likely to have an adverse reaction to iodine. However, research shows no such connection. Studies also indicate that having a shellfish allergy does not increase the likelihood of having an iodine allergy or an adverse reaction to intravenous contrast.

Natural Remedies

Managing a shellfish allergy involves strict avoidance of shellfish, which may even include avoiding touching or smelling it in highly allergic individuals. Researchers suggest that anyone who has had an adverse reaction to shellfish in the past should wear a Medic Alert identification and be trained in using an epinephrine auto-injector because future reactions may be more severe. Like with a peanut allergy, there are ways to boost your immune system and potentially reduce the severity of shellfish allergy symptoms with natural remedies.

1. Probiotics

Probiotic supplements enhance immune function and reduce the risk of developing food allergies. Research shows that the presence of probiotic bacteria in the intestinal microbiota is associated with protection against allergic diseases. Clinical improvements, especially in allergic rhinitis and immunoglobulin-sensitized eczema, have been reported in most of the published studies involving probiotics and allergies.

2. Digestive Enzymes

The incomplete digestion of food proteins may be linked to food allergies and can cause gastrointestinal symptoms. Taking digestive enzymes with meals can help the digestive system fully break down food particles and is a vital food allergy remedy for people with gastrointestinal shellfish allergy symptoms.

3. MSM (Methylsulfonylmethane)

Research suggests that MSM supplements may be effective in reducing allergy symptoms. MSM is an organic sulfur-containing compound that is used to improve immune function, lower inflammation, and help restore healthy bodily tissue. It can be used to relieve gastrointestinal issues and skin conditions associated with less severe shellfish allergy symptoms.

4. Vitamin B5

Vitamin B5 (or pantothenic acid) may be beneficial for people with allergies and asthma because it supports adrenal function. It is important in controlling nasal congestion, maintaining a healthy digestive tract, and boosting immune function.

5. L-glutamine

L-glutamine is the most abundant amino acid in the bloodstream and can help repair a leaky gut and boost immune health, which can be helpful during food allergy episodes. Research indicates that a leaky gut, or intestinal permeability, is likely to cause various pathologies, including allergies. Compounds like glutamine have the potential to inhibit inflammation and oxidative stress.

Shellfish Alternatives

The only way to truly avoid an allergic reaction to shellfish is to completely avoid eating and coming into contact with shellfish. Be aware that there may be traces of shellfish in seemingly harmless products, such as some Caesar salad dressings, soaps, cosmetics, sauces (like Worcestershire sauce), seasonings, vitamins, and insecticides. In a 2007 retrospective study over a five-year period, a total of 530 food reactions were reviewed. Researchers found that 119 reactions (over 22 percent) were considered to be due to hidden allergens, and 32 percent of these were anaphylactic reactions. Fish allergens hidden in those foods caused reactions in 35 percent of fish-allergic patients. This proves that people with a shellfish allergy must be vigilant and choose food alternatives that they know are safe. When looking for shellfish alternatives, it may be difficult to find foods with the same taste and texture as your favorite shellfish, but there are plenty of foods that offer the same nutritional benefits. For one thing, shellfish can serve as a source of protein. Protein, which is used in every single cell of the body, is crucial for building muscle mass, supporting neurological function, balancing hormones, aiding digestion, and boosting our mood. Protein foods are used to develop, grow, and maintain just about every part of the body. If you aren’t able to get your daily dose of protein from shellfish due to an allergy, there are plenty of other options available. Many shellfish also provide a good amount of iron, such as oysters, scallops, and clams. Iron plays a critical role in the body, and iron-rich foods provide us with energy, boost muscle and brain function, and support a healthy pregnancy. To get some of these same benefits, try the following shellfish alternatives:

1. Grass-Fed Beef

Grass-fed beef provides a healthy dose of iron and protein. Beef is also rich in potassium, B vitamins, and magnesium. If you can’t eat shellfish due to an allergy, eating a small portion of beef steak (about the size of your palm) is an excellent way to ensure you get enough nutrients in your diet.

2. Organic Chicken

Organic, free-range chicken is another lean source of protein and is versatile and can be added to many meals. A 2015 study published in Food and Nutrition Research found that consuming poultry meat as part of a vegetable-rich diet is associated with a reduced risk of developing overweight, obesity, cardiovascular diseases, and type 2 diabetes mellitus. Additionally, the collagen in chicken contains chondroitin and glucosamine, which help rebuild cartilage.

3. Beans

Beans, such as navy beans and black beans, are great alternatives for shellfish because they are high in protein and iron, along with many important micronutrients including potassium, magnesium, folate, and zinc. Beans are filling and can be added to stews, soups, salads, and many other meals like shellfish.

4. Lentils

Lentils are a favorite among vegetarians and vegans because they are high in protein and rich in nutrients. A 2009 study published in the Journal of the American Dietetic Association suggests that consuming lentils (and dry beans and peas) can improve diet quality in the U.S. population. Lentils have a variety of nutrients and phytonutrients that have been shown to have beneficial health effects, yet consumption levels in the United States are quite low. For people who can’t eat shellfish due to a food allergy, lentils can serve as a great source of protein and other important nutrients such as folate, manganese, phosphorus, thiamine, potassium, zinc, and more.

5. Free-Range Eggs

Eggs are sources of protein, fats, and micronutrients that play an important role in basic nutrition. They are easy to cook and provide important nutrients like selenium, riboflavin, vitamin D, vitamin B12, and phosphorus. There are numerous health benefits of eggs, including their ability to help improve eye health, prevent metabolic syndrome, reduce heart disease due to the omega-3 fatty acids, aid in weight loss, maintain brain health, and improve skin.

6. Chicken Liver

Chicken liver, or even beef and duck liver, is very high in nutrients and can be considered a superfood. It is a rich source of B vitamins, iron, and vitamin A. It also provides important minerals like phosphorus and magnesium. If you are trying to get the nutrients you are missing from shellfish elsewhere, look no further. You are getting the protein and iron from shellfish and much more.

Risks and Side Effects

A person allergic to shellfish who has never had an anaphylactic reaction before can still have one in the future. People with severe shellfish allergies should consult their healthcare providers about receiving epinephrine in case of an emergency anaphylactic reaction. Also, be aware that a second anaphylactic reaction, known as a biphasic reaction, can occur up to 12 hours after the initial allergic response.

Final Thoughts

• The popularity of shellfish has been increasing worldwide, but as a result, shellfish are the leading cause of food allergies in American adults.
• The approximate prevalence of shellfish allergy is estimated to be between 0.5 percent and 2.5 percent of the general population.
• The symptoms of a seafood allergy range from less severe issues like a runny nose and itchy throat to life-threatening anaphylaxis.
• Although the only true cure for any food allergy is to completely eliminate the allergen from your diet, there are natural remedies that can help reduce the severity of food allergy symptoms, such as probiotics, digestive enzymes, and vitamin B5.
• Shellfish provides protein and iron, among other important nutrients. People with a shellfish allergy can get these nutrients from foods like organic beef and chicken, eggs, beans, lentils, and liver.