Every year food allergies is starting to affect a larger group of people. Currently, it is present in about 8% of infants, about 5% of children and 3-4% of adults population in the US. Find out what are the common symptoms and how you can get tested to find out whether your body has allergic reaction to common allergens.
Atopic (IgE) allergy is characterized by an immediate and often strong reaction of the immune system and is mediated by so-called specific IgE antibodies (hence the name IgE reaction). Genetic predisposition is mainly responsible for its development, when the risk of its outbreak in a child who has both parents of allergy sufferers is up to 80%. If only one parent is allergic, then this risk is "only" 40 to 50%, and for children who do not have an allergy sufferer in the family, the probability is only 20 to 30%. So far, the only effective way to prevent and treat food allergies is to avoid allergens.
Allergy sufferers have different sensitivities to food allergens. Some respond to micrograms of trace amounts of allergens in food and may develop an anaphylactic reaction. Other small amounts tolerate and respond up to a milligram amount of allergen.
Atopic food allergy occurs when the body evaluates a food as "hostile" and arouses the immune system to defend itself against the enemy (IgE antibodies). The body begins to produce histamine and a number of other chemicals in its defense, the presence of which manifests itself in allergic reactions such as rhinitis, swelling, itching, indigestion, or worse, anaphylactic shock.
Poor health is not an isolated process, it is often a connection between several disease processes. Food allergy can manifest itself in various difficulties:
Usually caused by fresh vegetables, fruits, nuts, but also spices - is manifested by itching of the lips, runny nose, shortness of breath, mouth, throat, or swelling and redness around the lips. Sometimes the symptoms are limited to scratching in the throat, and the patient is often monitored at the neck ambulance as chronic nasopharyngitis. It occurs mainly in patients hypersensitive to pollen allergens (birch, alder, hazelnut, ragweed, hay fever…).
Exercise-induced food anaphylaxis - usually occurs from 30 minutes to 4-6 hours after ingestion of allergenic food (most often seafood, pasta, celery) and current physical activity, which otherwise does not represent an allergen in the individual.
Anaphylaxis - the most serious and most severe form of allergic reaction - multiorgan systemic reaction to a certain allergen - nausea, reddening of the skin, itching, impaired breathing, palpitations, marked feeling of fear, dizziness, sometimes spontaneous bowel movements, urination.
The components of foods that cause an allergic reaction are usually proteins. Many of them can cause an allergic reaction even though they are cooked or go through the process of digestion in the gut. It's good to know that some foods just need to be heat-treated - thermolabile allergens - and decomposed by heat and can then be safely consumed. Heat treatment also eliminates most allergens responsible for cross-allergy pollen - food. Exceptions are parsley, celery, nuts, peanuts, fish and some spices, which have allergens thermostable and do not change with heat.
The most common foods causing allergic reactions are:
Peanuts are among the most common food allergens, the insidious thing is that peanut fat is added to many foods to thicken the sauce, while often residual trace of the allergen is enough to trigger a reaction often life threatening. Peanuts have a cross-reaction with other legumes and are mostly a lifelong allergy.
Together with peanuts is one of the most common causes of death in patients with food allergies, patients allergic to wormwood pollen have a more frequent occurrence, cross-reactivity is in carrots and spices.
Honey allergy often occurs in pollen allergy sufferers and people allergic to bee stings.
Of the other allergens, wheat, soy and fish are also very common.
The anamnesis is very important and irreplaceable. By food allergy is meant if the patient's difficulties are linked to a particular type of food, if they recur, if the manifestation of symptoms does not depend on the amount of food, if the clinical difficulties disappear after omitting the suspect food, and if anti-allergy drugs help.
From laboratory tests, a blood test is used, namely: examination of total immunoglobulin E, specific food immunoglobulins E for individual foods and skin tests. However, these methods are relatively insensitive. A provocative stress test is used for real evidence of food allergy, but this test is very demanding and requires hospitalization of the patient.
But the best diagnostic method is if the patient keeps a food diary, listing all the foods he has eaten and the difficulties he has. In retrospect, it is possible to deduce which food is the most difficult for him.