From Big Medical Encyclopedia

EXOGENOUS ALLERGIC ALVEOLYTA (alveolitis exogena allergica, singular; Greek exo out of, outside + gennao to create, make; Greek alios another + ergon action; alveolites; a synonym allergic pneumonia) — group of the allergic pneumonia caused, as a rule, by adjournment in lungs of the cell-bound immune complexes consisting of antibodies and exogenous allergen; proceed in a look dif - fuzno - the litas disseminated alveo.

First detailed description of the most known look E. and. and., received the name «lung of the farmer», Campbell gave in 1932 (J. M of Campbell). Dikki (N. of A. Dickie) and J. Rankin in 1958 entered the term «hyper sensitive intersticial pneumonitis». The term «exogenous allergic alveolitis» was offered by J. Pepys in 1967. Because at this disease also bronchioles often are surprised, nek-ry researchers offer the term «bronkhio-loalveolit».

Etiology and pathogeny. Reason E. and. and. the allergen which got to an organism with inhaled air is. Allergens most often are disputes of fungi, to-rye are in rotten hay, maple bark, a sugarcane, is much more rare — vegetable dust, proteinaceous antigens, antigens of house dust, medicines (e.g., penicillin, drugs of Nitrofurum - a new row). In a course of a disease the size of the inhaled particles and their quantity are important (particles up to 5 microns easily reach alveoluses and cause a sensitization of an organism). AA. and. and. can result from influence of adverse factors of the production environment (inhalation of these or those substances) therefore separate types E. and. and. received the name by the nature of occupations of patients (see the table).

In a pathogeny E. and. and. the main role is played by the immunocomplex mechanism of damage of fabrics. The allergen which got to an organism causes a sensitization, at the same time antibodies, as a rule, precipitant to this allergen and belonging to IgG are formed (see the Sensitization). Antibodies (see) form with allergen cell-bound immune complexes (see Antigen — an antibody reaction), to-rye are postponed in walls of alveoluses and the smallest bronchioles, causing an alveolitis (see Pneumonia) and a bronchiolitis (see). Immune complex deposition is promoted by a hyperpermeability of a vascular wall, edges develops at inclusion IgE-mediated (the I type) allergic reactions; at the same time from mast cells or basphilic granulocytes vasoactive amines, and also a platelet activating factor are emitted, to-ry, in turn, promotes release of vasoactive amines (serotonin and a histamine) from thrombocytes. The platelet activating factor and vasoactive amines increase permeability of vessels and strengthen a chemotaxis of neutrophylic and eosinophilic granulocytes that leads to development of various inflammatory reactions (see Mediators of allergic reactions). To described you -

she to pathogenetic links allergic reaction of the slowed-down type (see the Allergy), accompanied with education in lungs of granulomas (see) can join. Its emergence is caused by features of allergen; usually it is particles, disputes of fungi. Formation of granulomas is caused also by insoluble cell-bound immune complexes. The granuloma passes a number of the stages which are coming to an end with scarring that leads to a pneumosclerosis in the development. In nek-ry cases allergens are fixed on cells of pulmonary fabric and change their antigenic properties that can lead to turning on of the tsntotoksiche-sky mechanism of damage of fabrics (see the Sensitization). In development E. and. and. pseudo-allergic mechanisms can take part. Complement activation the allergens received from nek-ry fungi or extracts, napr, from dust of mouldy hay, occurs on an alternative or classical way (see the Complement).


Pathological anatomy. In an acute stage of a disease in walls of alveoluses and bronchioles granulomas and inflammatory infiltration of hl come to light. obr. lymphocytes (see) and plasmocytes (see) with impurity of neutrophilic leukocytes. In alveoluses accumulation of exudate is possible (see). Granulomas consist of the epithelial cells surrounded preferential with lymphocytes and plasmocytes; they are not exposed to a necrosis (see). In walls of vessels and surrounding fabrics by immunofluorescent methods of a research (see the Immunofluorescence) deposits of immunoglobulins (see) and the third component of system of a complement often come to light (see). At late stages diffusion pulmonary fibrosis (see the Pneumosclerosis) with the centers of more expressed growth of connecting fabric is usually noted that leads to disturbance of very tectonics of lungs, uneven destruction of alveoluses, expansion of bronchioles and to emergence of zones of emphysema (see Emphysema of lungs). Fibrous changes are more expressed in upper parts of lungs.

Clinical picture. AA. and. and. can proceed in acute, subacute and hron. forms that depends not only on reactivity of an organism (see), but also on frequency and intensity of contact with allergen. So, at pigeon breeders the disease is shown in an acute form, usually after cleaning of a dovecot when they inhale a high dose of allergens. Fans of wavy popugaychik have a contact with allergens constant since birds are supported in apartments, but the dose of allergen inhaled for a unit of time is much less. In these cases the disease proceeds chronically more often.

The acute form of a disease in typical cases develops in 4 — 8 hours after contact with allergen and quickly passes after the termination of contact. The main symptoms are fever, an indisposition, a fever, feeling of a congestion (constraint) in breasts, perspiration, a headache and extremity pains, cough and short wind that reminds an acute respiratory disease. In blood the leukocytosis, S-reactive protein come to light, acceleration of ROE is frequent. In lungs at auscultation reveal crepitant rattles. Radiological the strengthened drawing of pulmonary fabric and melkoochagovy shadows, from almost inaudible to more outlined are defined. At the persons having atopic allergic diseases (see. And that-piya), at development E. and. and. typical the wedge, can precede a picture of a disease a bronchospasm (see) with a picture of bronchial asthma (see), edges develops the first 15 — 20 min. after inhalation of allergen. At the same time in lungs the whistling rattles are listened.

At a subacute form the general symptoms of a disease are less expressed. In some cases there is no clear communication with inhalation of allergen. Patients complain of fatigue, weight loss, short wind and cough. Objectively symptoms of bronchitis are defined (see). Radiological in lungs more expressed changes — diffusion nodular shadows, intersticial fibrosis come to light. At each subsequent aggravation more gradual return to health is noted.

Hron. form E. and. and. develops after repeated receipts in an organism of a large amount of allergen or at inhalation of its small amounts for a long time. Patients complain of the asthma arising even at small loadings.

At all forms E. and. and. it is noted restrictive, the form of respiratory insufficiency is more rare obstructive, (see).

The diagnosis is established on the basis of the anamnesis (the people who do not have predisposition to atopic reactions are ill preferential; the disease develops usually after long contact with allergen, during to-rogo there is a sensitization of an organism), the term of stage of latency (the acute form develops in 4 — 8 hour). wedge, pictures and data rentgenol. researches. The diagnosis can be confirmed with positive takes of skin tests (see) and serological researches. In diagnosis subacute and hron. forms in the absence of firm instructions on contact with allergens the large role is played by specific methods of a research. Usually apply intracutaneous tests (see. Skin tests), to-rye yield the most accurate results with «bird's» allergens (blood serum of birds or extracts from their dung), the least accurate — with fungal allergens because of a possibility of nonspecific reactions. In some cases carry out inhalation provocative tests (see).

Serological researches (see) allow to reveal different types of antibodies to estimated allergens at most of patients. Use a method of double diffusion on Oukhterlonya (see Immunodiffusion) and more sensitive — reaction of an immunofluorescence (see) and radio-immu but a logical method (see). Identification at the same time of precipitant and other antibodies to the corresponding allergens out of communication with the anamnesis and a wedge, a picture of a disease cannot serve as the proof of their participation in a pathogeny of a disease. Detection of these antibodies can be regarded only as an indicator of the former contact with this allergen, and their pathogenetic role can be confirmed with positive takes of provocative test.

Differential diagnosis is carried out with a sarcoidosis (see), at Krom not only lungs, but also other bodies are surprised, there are no communication with a profession or data on contact with any allergen, the hypercalcuria is noted, radiological increase radical limf, nodes, etc. often comes to light; with an aspergillosis of lungs (see Pneumomycoses), to-ry a thicket Aspergillus fumigatus while E is caused. a. a. — Aspergillus clavatus. It is necessary to differentiate E also. and. ampere-second pneumonia inf. origins (see Pneumonia). At the same time it is necessary to consider that at a lung fever segmented or share blackout radiological is defined, at focal pneumonia — lobular infiltration.

Treatment consists in the termination of contact with allergen, use of the corticosteroids promoting at an acute form of a disease to more bystry recovery of the broken functions. At subacute and especially hron. the effect of corticosteroids is less expressed to a form of a disease.

The forecast favorable at identification of allergen and the prevention of contact with it. In far come cases the forecast adverse, development of a pulmonary heart is possible (see).

Prevention of aggravations E. and. and. and a sensitization of an organism comes down to the prevention of contact of the patient with the corresponding allergen that is reached, e.g., by change of technology of production for the purpose of reduction of concentration of allergen in inhaled air, uses of respirators (see); in some cases change of a profession is recommended.

See also Easy.


Bibliography: Pytskiyv. And., Adria

but in and N. V. and And r t about m and with about in and A. V., Allergic diseases, M., 1984;

Turner-at orvikm. Immunology of lungs, the lane with English, M., 1982; Campbell J. M of Acute symptoms following work with hay, Brit. med. J., v., 2, p. 1143, 1932; Dickie H4 As a * R a n k i n J,

Farmer’s lung, an acute granulomatous interstitial pneumonitis occurring in agricultural workers, J. Amer. med. Ass., v. 167, p. 1069, 1958. V. I. Pytsky.