Fish allergy: causes, manifestations and solutions

Fish allergy is quite a rare problem. Although not as common as, for example. pollen allergyit’s possible that it may not manifest itself in humans. In this article, we will look at what causes this type of allergy, how to recognize it and what to do so that, despite the allergy, the body still has enough of the health benefits that fish contains.

What does fish contain?

Fish is a rich source of nutrients. The amount of substances varies from one species to another, of course, but they are mostly found in:

• Protein – Fish is an excellent source of high quality protein, which is essential for the formation and repair of cells in the body.
• Omega-3 fatty acids – Many fish contain omega-3 fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These fatty acids are important for heart, brain and eye health.
• Vitamins – Fish provide the body with a variety of vitamins, including vitamin D for bone health, vitamin B12 important for the nervous system and vitamin A to support eyesight.
• Minerals – They also contain minerals, specifically iron, zinc, calcium and phosphorus, which affect and are often essential for various functions in the body.
• Iodine – Certain species of fish form a good reservoir of iodine. This is crucial for proper thyroid function.
• Selenium – Fish can also be a rich source of selenium, which is an antioxidant that helps protect cells from damage.

Often due to environmental contamination, fish unfortunately contain harmful substances in addition to beneficial ones. These include:

• Heavy metals – Some species of fish may contain mercury and lead that get into the sea. Excessive mercury in the body can negatively affect the nervous system.
• Polychlorinated biphenyls (PCBs) – These chemicals have been widely used in industry in the past and can accumulate in the tissues of some fish. PCBs are considered potential carcinogens and can have a negative impact on the endocrine system.
• Dioxins – Dioxins are another group of toxic substances that fish can contain. They are carcinogenic and damage the immune system.
• Plastics and microplastics – In some marine areas, fish can be contaminated with plastic particles that are dangerous to human health.

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What is a fish allergy?

A fish allergy is not a reaction to the harmful substances mentioned a moment ago, but an immune reaction of the body to proteins, which are technically called proteins. This form of allergy causes several different and unpleasant symptoms. The symptoms of a fish allergy can appear immediately after eating fish or even several hours afterwards.

Fish allergy in children

In children, it is more difficult to identify the symptoms of fish allergy, because at a young age they are not able to fully describe their feelings. Skin symptoms and digestive problems are more common, but otherwise the cause and treatment of fish allergy in children is the same as in adults.

Read about the most common allergies in children.

Fish allergens: what causes fish allergy?

In both freshwater and saltwater fish, fish proteins are the cause of fish allergy. The main fish allergens include:

• Parvalbumin – Parvalbumin is the most common allergen. It is mainly found in bony fish, such as sardines, salmon, trout, pike and cod.
• Tropomyosin – Protein Tropomyosin is more commonly found in seafood. For people with allergies, shrimps or crabs tend to be problematic.
• Thiaminase – Some species of fish may contain thiaminase, an enzyme that can cause an allergic reaction in some individuals.
• Enolase – Enolase is another protein that could be the cause of fish allergy.

In general, people allergic to fish should avoid carp, cod, plaice, herring, mackerel, sardines, salmon, sea bass, swordfish, tilapia, trout and tuna. These fish are the most risky in terms of fish allergy.

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Symptoms of fish allergy

Symptoms of fish allergy can be mild or more severe. If you develop any of the following symptoms after eating fish or fish products, do not underestimate them. These may include:

• Itching or redness of the skin,
• rash or hives,
• swelling on various parts of the body,
• sneezing,
• a runny or stuffy nose,
• cough or shortness of breath,
• scratching in the throat or chest pain,
• nausea or vomiting,
• diarrhea,
• abdominal pain,
• general fatigue or weakness,
• dizziness,
• anaphylaxis in extreme cases.

Learn how to recognize an allergy.

Diagnosis of fish allergy

Diagnosis of fish allergy must take the form of a professional medical examination. Self-treatment or undiagnosed allergy can lead to very serious consequences.

Skin prick tests are the most commonly used method for diagnosis . A small amount of the allergen, in this case fish protein, is injected onto the skin using a special needle. In allergy sufferers, a red spot pops up.

Blood tests are another option . These are tests for specific IgE antibodies that are formed in the body in response to the presence of one or more allergens. The fact that the results are obtained from the blood makes them very reliable.

You should see an allergist even if you have only a slight suspicion of allergies. You will be reassured that your trip will not be in vain home allergy tests.

Treatment of fish allergy

A visit to the doctor is important not only to establish a diagnosis, but above all to determine an adequate treatment tailored to the person according to the severity of the problem.

The first step in treating a fish allergy is to eliminate fish and fish products from the diet, or an elimination diet. When shopping for food, it is important to watch labels carefully and avoid anything that contains fish allergens.

If you want to indulge in some of the healthy components of fish, such as omega-3 fatty acids, vitamin D, zinc or iron, you can try dietary supplements. Just to reiterate the need to read the package insert. Some dietary supplements may contain Parvalbumin and other fish proteins.

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In people with more severe symptoms, fish allergy is often treated with:

• Antihistamine – Antihistamines are medications that help relieve allergy symptoms, especially itching, redness and swelling. These medicines block the effects of histamine, which is released during an allergic reaction.
• Corticosteroids – In some cases, local or systemic treatment with corticosteroids may be prescribed to suppress inflammation.
• Adrenaline autoinjector – People with a serious history of fish allergy can get an adrenaline autoinjector. This is a pen with a small needle filled with adrenaline that the patient can use to help themselves in the event of anaphylaxis.

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