Food Allergies - Causes, Symptoms & Treatment

A food allergy is a condition in which the body reacts negatively to the food it eats. It is an immune system response to a dietary protein.

   

What is a food allergy?

A food allergy is a condition in which the body reacts negatively to the food it eats. It is an immune system response to a dietary protein. Food allergy differs from other reactions of the body to food, such as food intolerance, also from drug intolerance, as well as toxin-mediated reactions. Food intolerance is the inability of the body to process food properly, which is usually due to the lack of certain enzymes, and in food allergy, the immune system generates a response with antibodies to the change in food in the body.

Allergy is a changed or impaired reactivity of the body to the impact of certain factors - allergens. Getting into the body, allergens provoke the body to produce neutralizing antibodies. Initially, the reaction of the interaction between allergens and antibodies may go unnoticed. But with each subsequent introduction of the allergen, its intensity increases, which manifests itself in various clinical symptoms.

Causes of an allergic reaction

The allergic reaction occurs when the susceptible organism is exposed to the action of a specific protein. Since the body perceives this protein (allergen) as a threat, it begins to produce a specific antibody substance - immunoglobulin E (IgE). Allergy sufferers tend to produce higher amounts of IgE. After being exposed to this specific protein, the body responds by producing a large amount of these antibodies. These newly produced antibodies bind to special blood cells called basophils and special cells in soft tissues called fat. These cells are then "simulated" to release histamine, which causes allergic symptoms. In other words, the immune system releases large amounts of substances, including histamine, to protect the body. These substances trigger a number of allergic symptoms,

Any food protein that triggers an immune response is called a food allergen. More than 12 million Americans have been diagnosed with food allergies, and the number is constantly growing. 6-8% of children under the age of 3 suffer from some kind of food allergy, nearly 4% of adults too. It is also the cause of about 30,000 emergencies and 100 to 200 deaths each year in the United States. The most common food allergies in adults are to fish and seafood, peanuts and tree nuts, and eggs. For children, the top places are milk, eggs and peanuts. Treatment consists of eliminating the problem foods from the diet, which means all forms of this food in which it can enter the body - even touching or inhaling particles in extremely sensitive people (the downy shell of the kiwi fruit).

Signs and symptoms of food allergy

Classical immunoglobulin-E (IgE)-mediated food allergies are classified as rapid type-I hypersensitivity. Reactions have a rapid and acute onset (from a few seconds to 1 hour) and may include:

• Angioedema: swelling of the soft tissues, usually the eyelids, face, lips and tongue. It is possible to turn into severe swelling of the tongue, larynx and trachea, which will lead to respiratory obstruction and serious breathing difficulties, even suffocation;

• Itching and burning of the mouth, throat, eyes, skin;

• Nausea, vomiting, diarrhea, stomach cramps and abdominal pain. This group of symptoms is referred to as gastrointestinal hypersensitivity or anaphylaxis;

• Nasal congestion

• Scratching in the throat and shortness of breath;

• Anaphylactic shock: an acute allergic systemic reaction affecting the whole body that can lead to death.

Important differential diagnoses:

• Lactose intolerance: this condition usually develops later in life, but is also often seen in young patients, children, infants. It is due to an enzyme deficiency or immaturity of the lactase enzyme, not an allergy. The condition is common among eastern peoples;

• Celiac disease: an autoimmune disease characterized by intolerance to wheat gluten;

• C1 esterase inhibitor deficiency (hereditary angioedema).

The most common food allergies are to:

• milk

• eggs

• peanuts

• tree nuts

• fish

• Seafood

• soy

1. Milk - intolerance to some of the proteins in milk - casein and lactoglobulin. Typical symptoms are swelling, itching, bronchospasms, fever, drop in blood pressure, spasms and disorientation. Avoid products containing: casein, sodium caseinate.

2. Eggs - eggs are made up of different proteins, many of which are allergens. There are four main proteins in the protein causing allergic reactions - ovomucoid, ovalbumin, ovotransferrin and lysozyme. Ovalbumin is the main allergen, 50% of the egg white. Most people are allergic to the egg white, but some are also allergic to the yolk. The names of the allergens in egg yolk are apovitelnis I, apovitelnis VI and phosvitin. The symptoms are allergic rhinitis, asthma, dermatitis, gastrointestinal problems. It's good to know that some egg substitutes contain egg white.

3. Peanuts - allergic reactions are caused by proteins in peanuts binding to immunoglobulin E (IgE). Sometimes even traces of them can cause allergic reactions. Seven proteins from different families - vacillins, conglutins and glycinias - react with human IgE and induce an immune response in those susceptible to these allergies. However, the allergenicity of refined peanut oil is controversial.

4. Tree nuts - these are hazelnuts, walnuts, cashews, almonds, chestnuts, pistachios. Contamination in the production of various products must also be taken into account - for example, in milk chocolate there may be traces of nuts if such a product is produced there.

5. Fish - these allergies are due to proteins found in the muscle tissue of fish. Sometimes allergies are more specific and are usually associated with the so-called occupational diseases - that is, for people whose workplace is related to the processing or extraction of fish.

6. Shellfish - these are allergies to proteins contained in molluscs - clams, shrimps, oysters, crabs. They are most often associated with shrimp.

7. Soy - allergies to about 15 proteins contained in soy. Research shows that most of those prone to soy allergy can use products that contain soy lecithin or soy oil because the reactions are with the proteins contained in soy.

8. Wheat flour - these are allergies to the protein found in wheat.

In general, the most common food allergies develop in childhood. 55% of children who are allergic to milk, eggs, wheat and soy develop these allergies by the time they are 3 years old. When it comes to nuts and seafood, 25% of children with such allergies develop them by age 3.

 

PREMIUM CHAPTERS ▼

Treatment of food allergies (PREMIUM)

Although there is no complete  cure for food allergies, medications can help with minor symptoms. Antihistamines can be used to treat symptoms such as rash, runny nose, and abdominal pain associated with an allergic reaction. For difficulty breathing or asthma attacks ("attacks") as a result of a food allergy, a bronchodilator is recommended. But remember: For a breathing problem caused by an allergy, it's important to seek emergency medical attention right away, even if breathing medications have been given to treat the reaction at home. Epinephrine is often used to treat severe allergic reactions. Medicines that increase heart rate and blood pressure, such as epinephrine, are often needed to control various severe allergic reactions.

Eating in the presence of a food allergy (PREMIUM)

Eating can be a challenge in such a case. To treat allergies, foods containing allergens must be eliminated from the diet. You will need to familiarize yourself with food labels and ingredient lists so that you can avoid the allergen.

• Milk: Avoid cheese, butter, cream and yogurt. Skim milk is also avoided, as are ingredients such as casein and whey.

• Eggs: Avoid sweets, pasta, mayonnaise and egg substitutes, foods that contain ovalbumin. Some fresh pasta and soups can also be made with eggs. In addition, the doctor may recommend avoiding the flu shot if you have an egg allergy because this vaccine contains small amounts of egg protein.

• Soy: Avoid soybeans, soybean oil, soy sauce, soy protein, soy oil, and tofu. Also avoid any foods that contain lecithin in the ingredient list.

• Peanuts: Avoid all foods that contain nuts, including peanut flour and peanut oil, Asian food (which is often prepared with peanut oil), egg rolls, chocolate, desserts, and any pasta that may contain nuts. If there is hydrolyzed vegetable or animal protein in the food ingredients, you should avoid it because it may contain nuts. Although peanuts and tree nuts are 2 different foods and are not really similar, if you are allergic to peanuts it is recommended to avoid tree nuts (and vice versa) because there is about 30% cross-reactivity to the two allergens.

• Tree nuts: Avoid almonds, Brazil nuts, walnuts, cashews.

• Crustaceans: Avoid crabs, lobsters, snails, clams and oysters, as well as other types of crustaceans.

Pseudo food allergies (PREMIUM)

Pseudo-allergies are not related to the immune system, although they can present with the same symptoms as "true" allergies. They are provoked by foods containing histamine or leading to the formation (release) of histamine during chemical reactions, for example in the digestive system. Canned tuna or mackerel, for example, can be high in histamine, which directly leads to the triggering of symptoms just like those of an allergic reaction. Having a similar histamine reaction does not mean you are allergic to tuna or mackerel.

Other food products can also trigger pseudo-allergies, such as some food additives (colors, preservatives, flavors). They should be avoided. Among the approximately 3,000 commonly used food additives, the most common causes of hypersensitivity reactions are:

Preservatives:

• sulfites and their derivatives: E 220-227

• nitrates: E 249-252

• benzoic acid and its derivatives: E 210-219

• sorbitol acid

Antioxidants:

• Butyl-hydroxyanisole: E321

• Butyl-hydroxytoluene: E 321

Dyes:

• Tetrazine: E102

• yellow-orange S: E 110

• azorubin: E 122

• Magenta: E 123

• cochineal red: E134

• erythrosine: E127

• brilliant black BN: E 151

Scents:

• Glutamates: In 550-553

 

Dietary nutrition for food allergies (PREMIUM)

Substitutes for cow's milk and its derivatives (if there is no casein allergy):

• Sheep's milk and sheep's cheese from 100% sheep's milk, Roquefort (if there is no mold allergy)

• Goat's milk and goat's cheese

• Mare's milk (if there is no allergy to horse hair)

• Buffalo milk and buffalo cheese

• Soy milk and its products (e.g. tofu) - can be used in cases of allergy to casein (in the absence of allergy to soy).

It is good to know that some types of high-fat cheeses from whole cow's milk cause complications only in case of acute allergy to cow's milk. It is perceived better if the cheese is boiled or baked. Processed cheese is easier to take because it undergoes heat treatment during production, and hard cheeses, especially those with a long shelf life, are usually worse tolerated. With a slight allergy to cow's milk, cottage cheese, condensed milk, cream can sometimes be used as an addition to meals. In 98% of cases, cow butter in small amounts is well tolerated. In case of severe allergies, it can be replaced with vegetable margarine.

Substitutes for flour, starch and sprouted grain (wheat germ) for gluten allergy:

• Potato flour and starch

• Chestnut flour

• Corn flour and starch

• Bean flour (in the absence of an allergy to beans)

• Oat flour

• Oat flakes

• Rice flour and starch

• Soy flour (in the absence of an allergy to soy)

• Barley flour (in the absence of an allergy to malt)

When using bread, it should be borne in mind that well-heated flours less often cause allergic reactions. Rye crackers also rarely cause allergies, and white bread has a greater allergenic effect than rye or wholemeal bread.

Food allergy is not for life!

Intolerance to animal proteins decreases as the child grows, if he was allergic. For example, some children begin to tolerate egg yolk after the age of 1 year. Allergies can come and go throughout life, as well as periods of remission and exacerbation.