In recent decades, the occurrence of allergic diseases has become more and more frequent. Almost a quarter of the population of developed countries suffers from allergic diseases, while in the USA every fifth person suffers from this disease. Allergic diseases, which are often associated with the developed world, are reaching almost epidemic proportions. Allergies are caused by allergens, substances with which the body is constantly in contact, and which are found all around us: in the air and we inhale them, enter the body with food, drink and taking medicines. While these substances are harmless to most people, they can cause an allergic reaction in some. The body can cause a reaction to the allergen immediately after contact or a few days later. Allergic reactions can range from mild to very serious and even life-threatening. The frequency of allergies is increasing in newborns and children, making them the most common chronic disease in childhood. Allergies in children often start as nutritional allergies, then develop into atopic dermatitis, and later into allergic rhinitis and asthma. In most cases, allergies are inherited from parents. Its development is influenced by external and internal factors. Internal factors are hereditary and cannot be changed, while external factors include exposure to allergens, stress, diet and similar things we can control. Typical allergy symptoms include runny and stuffy nose, itchy and red eyes, difficulty breathing, sneezing, coughing, hoarseness, headache, rash, skin eczema, vomiting and loose stools. Since every allergic reaction has a specific allergen as the cause, it is necessary to carry out allergy testing in people with these symptoms. In medicine, there are several techniques for conducting allergy tests, the most common of which include blood tests and skin tests. The testing is performed by a specialist doctor, and the results help in making an accurate diagnosis.