Allergy is an exaggerated and misdirected immune response to substances with antigenic properties. Any substance that the body identifies as foreign or potentially dangerous and produces antibodies against is called an antigen. Antigens that trigger allergies are referred to as allergens. All individuals naturally produce a type of antibody called IgE, but allergic individuals tend to produce it in excessive amounts. As a result, the immune system reacts to otherwise harmless substances as if they were threats, causing various symptoms even in the absence of any real danger.
Allergy is essentially the body’s unusual (exaggerated) response to environmental factors called allergens (chemical substances, microorganisms and their metabolic byproducts, foods, etc.).
The most common allergens include food products, plant pollens, and house dust. Others include leather goods, animal dander, feathers, cosmetics, household chemicals, medications, certain plant oils, and sunlight. Allergens can enter the body through the skin, respiratory tract, or gastrointestinal tract.
The physiological mechanism of allergy is based on antibody formation, which may lead to increased or decreased sensitivity. Allergies typically manifest through intense irritation of the mucous membranes, skin rashes, and general weakness. Diseases such as bronchial asthma are rooted in allergic mechanisms.
Household Allergies
An allergy is an excessive sensitivity or immune system response to a substance. This is considered a dysfunction of the immune system. Allergic diseases include hay fever (pollinosis), allergic rhinitis, bronchial asthma, atopic asthma, food allergies, and drug allergies. Pollinosis is a seasonal allergic reaction to pollen from certain trees, grasses, or flowers, typically affecting the respiratory system. Symptoms such as itching around the eyes and nose, sneezing, and nasal congestion typically occur during the spring, summer, or autumn and subside in winter.
When allergens enter the body, they bind with antibodies to form antigen-antibody complexes, which trigger the release of biologically active substances such as histamine, serotonin, acetylcholine, prostaglandins, and kinins—laying the groundwork for allergic reactions.
If these complexes form in the bloodstream, they can lead to immediate allergic reactions, such as anaphylactic shock, serum sickness, bronchial asthma, urticaria, and Quincke’s edema. Delayed allergic reactions, such as allergic contact dermatitis, toxic-allergic dermatitis, bacterial allergies, transplant rejection reactions, and autoimmune diseases, are also possible.
The key principle of allergy treatment is avoiding contact with the identified allergen (once accurately diagnosed). However, this is not always feasible, especially during high-pollen seasons. In many cases, the goal is to reduce exposure (e.g., to house dust or animals).
During acute allergic episodes, various medications are used, including antihistamines and corticosteroids. Some are broad-spectrum, while others are condition-specific (e.g., for asthma).
Food Allergy
Food allergies can manifest through skin rashes, redness, swelling, and even life-threatening symptoms such as breathing difficulties. Common triggers include fruits and vegetables, citrus fruits, milk, honey, cooked dishes, and sweets. Food allergy is defined as an allergic reaction to normally harmless food ingredients. Although any food can cause allergies, the most common triggers are: milk, eggs, fish, shellfish, soy, wheat, tree nuts, and especially peanuts. People allergic to peanuts may also react to other legumes such as peas, lentils, and soybeans.
Symptoms of food allergy
Reactions usually begin a few minutes to two hours after consuming the food. In severe cases, even touching or smelling the food can provoke a response. Early symptoms include swelling and itching of the lips, mouth, or throat. Gastrointestinal symptoms may include nausea, vomiting, cramps, and diarrhea. Skin symptoms like hives, eczema, and redness are also common.
The treatment involves strict elimination of the allergen from the diet. A hypoallergenic diet (typically involving rice, apples, and lettuce) should be followed for several weeks. Other foods can gradually be reintroduced to identify the allergen. All elimination diets must be supervised by a doctor or dietitian to avoid nutritional deficiencies.
Drug Allergy
Among allergic conditions, drug allergies are the most dangerous. Reactions can range from rashes to anaphylaxis and even death. They usually occur when medications are taken without proper medical supervision or without considering pre-existing health conditions.
Drug overuse is also a major contributing factor. It is recommended to limit medication intake as much as possible and only under medical supervision.
Seasonal Allergies
These allergies are linked to seasonal environmental changes, such as tree pollination starting in March and lasting until May, and reactions to weeds and ragweed in July and August.
Typical symptoms affect the nose, throat, and eyes and include:
Runny nose
Itchy and watery eyes
Frequent sneezing
Skin redness and itching
Headache
Breathing difficulties or shortness of breath