Exogenous allergic alveolitis in children

Exogenous allergic alveolitis (ICD-10 code: J-67) refers to the group of interstitial lung diseases of known etiology. Exogenous allergic alveolitis is a hypersensitive pulmonitis with diffuse lesions of the alveoli and interstitium. The frequency of occurrence in children (usually at school age) is lower than in adults (the incidence of exogenous allergic alveolitis is 0.36 cases per 100,000 children per year).

Causes of exogenous allergic alveolitis

Exogenous allergic alveolitis is caused by the inhalation of organic dust containing various antigens, microorganisms (for example, thermophilic actinomycetes from hay, the so-called easy farmer), aspergillas and penicillas. Animal and fish proteins, insect antigens, aerosols of antibiotics, enzymes and other substances. In children, the most frequent cause of development of exogenous allergic alveolitis is contact with the feather and litter of birds (the so-called easy lovers of wavy parrots or light blue people) and elevator dust. In adults, the spectrum of allergens is much wider. Such as dust of cotton (babesiosis) or sugar cane (bagasse), sawdust, mushroom spores (light mushrooms), fungal dust in the production of cheeses (light cheese), in patients with diabetes insipidus - inhalation drugs of the posterior lobe of the pituitary gland, etc.

What causes exogenous allergic alveolitis?

Pathogenesis of exogenous allergic alveolitis. In contrast to atopic bronchial asthma, in which allergic inflammation of the bronchial mucosa is a consequence of the IgE-dependent type I reaction, the development of exogenous allergic alveolitis is formed with the participation of precipitating antibodies belonging to immunoglobulins of classes IgG and IgM. These antibodies, reacting with the antigen, form large-molecule immune complexes that are deposited under the endothelium of the alveolar capillaries.

Symptoms of exogenous allergic alveolitis. Acute symptoms occur 4-6 hours after exposure to a causally significant antigen. There is a short-term increase in body temperature to high figures, chills, weakness, malaise, pain in the limbs. Cough has a paroxysmal character with a difficultly separated sputum, a dyspnea of a mixed nature at rest and is enhanced by physical exertion. Remote rales, cyanosis of the skin and mucous membranes are noted. On examination, attention is drawn to the absence of any signs of an infectious disease (primarily ARVI - absence of hyperemia of mucous membranes of throat, tonsils, etc.).

Symptoms of exogenous allergic alveolitis

Diagnosis of exogenous allergic alveolitis

The clinical picture of exogenous allergic alveolitis does not depend on the type of allergen. In case of acute onset, symptoms resembling flu (chills, fever, headache, myalgia) appear a few hours after a massive contact with the allergen. Appear dry cough, shortness of breath, scattered small- and medium bubble wet rales; there are no signs of obstruction. The picture of asthma is observed in children with atopy. When the allergen is eliminated after a few days or weeks, the symptoms disappear / subside.

In the hemogram for this phase of the disease is not characteristic of eosinophilia, sometimes there is a slight leukocytosis with neutrophilia.

On the roentgenogram of chest organs, changes are noted in the form of small (miliary) focal shadows located mainly in the middle of the lungs. Sometimes describe a picture of a decrease in the transparency of the lung tissue - a symptom of "frosted glass." Multiple infiltrative cloud-like or more dense shadows, characterized by reverse development during weeks and months, can also be noted. In some cases, pronounced radiographic changes are not observed. Exogenous allergic alveolitis is characterized by the disappearance of radiological changes after the termination of contact with the allergen (especially against the background of glucocorticoid therapy).

Diagnosis of exogenous allergic alveolitis

Treatment of exogenous allergic alveolitis

Obligatory is the elimination regime (cessation of contact with the allergen). In the acute phase, glucocorticoids are prescribed, for example prednisolone up to 2 mg / kg per day orally. Reduce the dose should be gradually from the beginning of the positive dynamics of the clinical picture (reduction of dyspnea, cough, normalization of FVD). Then a maintenance dose of prednisolone 5 mg per day for 2-3 months is prescribed. Option: pulse therapy with methylprednisolone 10-30 mg / kg (up to 1 g) 1-3 days, once a month for 3-4 months.

Treatment of exogenous allergic alveolitis

Forecast of exogenous allergic alveolitis

The acute phase of exogenous allergic alveolitis shows a favorable prognosis when contact with allergens is stopped and timely adequate treatment. When the disease progresses to the chronic stage, the prognosis becomes quite serious. Even after cessation of contact with the allergen, the progression of the disease continues and is not amenable to therapy. The situation is aggravated with the development of the pulmonary heart.

[1], [2]