Allergic conditions can take many forms, which can occur at almost any age, and their incidence in children, adolescents and young adults is constantly increasing worldwide. They can affect the airways (chronic cough, shortness of breath, asthma, laryngeal edema), the eyes (itchy eyes, conjunctivitis, allergic conjunctivitis), the nasal mucosa (nasal congestion, chronic rhinitis, hay fever), the skin (eczema, rashes, hives) and intestinal tract (food sensitivity, food allergies). Genetic predisposition and environmental influences are involved in their development, and the triggering of certain diseases can be considered as pathological reactions to external influences (mostly so-called allergens).