Allergy

ALLERGY (from Greek allos- other and ergon- work), unusual, perverted reactions of the body. The concept of A. in modern pathology unites numerous reactions of the body, undoubtedly very different in their pathogenesis. In essence, every sick organism, due to disruption of the harmony of physiological functions, shows a tendency to allergic reactions. Allergic reactions of the body differ from normal ones quantitatively (increased sensitivity) and qualitatively (perverted reaction). Allergic states of the body occur especially easily during acute and chronic febrile infections under the influence of intoxication. Manifestations of A. usually include: various types of idiosyncrasies, diverse forms of anaphylaxis (see), reactions of the body to protein therapy and non-specific vaccine therapy, phenomena of para-immunity (see) and others. Allergy, skin. The method of artificial introduction of allergens (sensitizers) is widely used in dermatology for both diagnostic and therapeutic purposes. The best therapeutic results have been obtained by the method of active anaphylaxis. Local allergic reactions have acquired particular diagnostic interest. Most tests for skin sensitivity do not give a specific reaction; they only allow one to judge the increased state of readiness (Bereitschaft) for irritation of the epidermis or blood vessels. The allergic state is more often observed in that group of skin diseases in which the factors of hereditary or acquired constitutional defects, depending on one or another metabolic disorders, are more pronounced. Morphologically, in the skin with A., erythema, blister, hemorrhage are more often encountered than other primary elements; nosologically - eczema, urticaria. Examples: appearance of urticaria when eating crayfish, berries, when taking certain medications orally (antipyrine, etc.); bullous rashes caused by external application of iodoform. Allergens, substances that cause an allergic reaction when introduced parenterally into the body (see Anaphylaxis).