From Big Medical Encyclopedia

ATOPY (grech, atopia strangeness, singularity) — group of allergic diseases which main role in development belongs to genetic predisposition.

The term «atopy» introduced in 1922 for the first time. Cook (A. F. Sosa) for definition of hereditary forms of hypersensitivity of an organism which are characterized by existence of humoral antibodys and hl meet. obr. at people. Later it was established that many characteristic for And. the phenomena occur also at dogs, cattle, walruses and other animals.

And. at the person can arise in relation to many groups of allergens: pollen, dust, food, medicinal, and also to insecticides etc. These allergens sometimes call still atopenam. Carry some forms to atopic allergic diseases bronchial asthma (see), hay fever (see. Pollinosis ), allergic rhinitis (see), allergic dermatitis (see), small tortoiseshell (see), a Quincke's disease (see. Quincke hypostasis ) and some other manifestations of allergic reactions from various bodies and systems (a gastroenteritis, conjunctivitis, aphthous stomatitis, epileptiform attacks, a medicinal leukopenia and an agranulocytosis, a Werlhof's disease, hemolitic anemia).

According to Krayp (L. Criep, 1966), And. suffer from 6 — 10% of the population of the globe. Approximately at 1/3 patients And. it is shown in the first years of life. The allergy in the family anamnesis meets more often, the earlier it is shown at children.

Mechanism of development various manifestations And. it can be presented on the basis of patterns of formation of the allergic reactions of immediate type consisting in consecutive change of immunological, patokhimichesky and pathophysiological changes (see. Allergy ). Main feature of an immunological stage And. tendency to formation of kozhnosensibiliziruyushchy antibodies or reagins is (see. Antibodies ), easily revealed by means of Prausnitts's reaction — Kyustnera (see. Prausnittsa-Kyustnera reaction ). Concentration of reagins in blood is proportional to degree of a skin sensitization, but not always corresponds to degree of clinical sensitivity (expressiveness of symptoms). Compound of reagins with allergen on cells leads to alteration of these cellular structures, to release from them biologically active agents in what the patokhimichesky stage of atopic reactions consists. Effect of the released biologically active agents and the complex allergen — reagin on various fabrics effectors leads in turn to those pathophysiological changes which define an external picture A. — increase in vascular permeability, hypostasis of fabrics, hypersecretion, reduction of smooth muscles. Morphological changes in fabrics at And. the same, as at an anaphylaxis — hypostasis with cellular infiltration, hl. obr. histiocytes and eosinophils, and fibrinoid degeneration of collagen.

Though in a basis And. and an anaphylaxis the same mechanisms lie, between them there are distinctions. Unlike an anaphylaxis, edge is caused by artificially preferential proteic matters, And. represents the hereditary, spontaneously appearing hypersensitivity to substances of both the proteinaceous, and nonprotein nature.

Consider that tendency to atopic allergic diseases can be transmitted through one couple of allelic genes of N and h from which the N defines absence of an allergy, h — its existence. Three various genotypes are possible: HH — normal; hh — allergic (at individuals with such genotype symptoms of a disease can appear before achievement of puberty), Hh — individuals with such genotype can be or healthy carriers, or the allergy at them develops after puberty. However the hereditary factor defines only predisposition of an individual to a sensitization. A necessary condition for implementation of this predisposition is the contact with allergen.

Characteristic symptoms of atopic diseases are frequency, duration and a recurrence.

Diagnosis And. facilitates existence it in the family anamnesis, an eosinophilia in blood, fabrics and secrets (nasal slime, saliva). However it is final only specific diagnosis can validate the estimated diagnosis: skin (scarifying, intradermal) and provocative (conjunctival, nasal, inhalation) allergy diagnostic tests (see). Value of methods of definition of reagins on the isolated bodies, and also cellular diagnostic tests remains relative until recently, and they can be applied only in combination with traditional methods of specific diagnosis at the patient with an atopy.

Therapy And. it is carried out by impact on various phases of allergic process. However the most effective method of treatment is specific impact on an immunological phase of allergic reaction. Success of specific treatment is explained by the fact that at many types And. (a pollinosis, allergic rhinitis, bronchial asthma, etc.) identification of the allergen responsible for developing of a disease is possible.

There are two main ways of specific therapy: 1) termination of contact of the patient with allergen; 2) use of a method of specific desensitizations (see). The first way is more preferable, but is not always almost feasible. Therefore generally apply specific desensitization, edges yields good results. During bad attacks of an atopic disease and when allergen is unknown, the symptomatic treatment (adrenaline, ephedrine, an Euphyllinum, etc.), and also treatment is carried out by antihistaminic and glucocorticoid drugs.

Bibliography: Boyd U. Fundamentals of immunology, the lane with English, page 391, M., 1969, bibliogr.; To r and y p L. Clinical immunology and an allergy, the lane with English, page 84, M., 1966, bibliogr.; Sosa A. F. ampere-second of au-au of k e R. A. Classification of phenomena of hypersensitiveness, J. Immunol., v. 8, p. 163,1923; Pathogenese und Therapie allergischer Reaktionen, hrsg. v. G. Filipp, S. 16, Stuttgart, 1966, Bibliogr.

A. I. Ostroumov.