The development of toxic fibrosing alveolitis (ICD-10 code: J70.1-J70.8) is due to the toxic effects of chemicals on the respiratory department of the lungs, as well as the damaging effect of immune complexes. In children, toxic fibrosing alveolitis is more often associated with the intake of various drugs (sulfanilamides, methotrexate, mercaptopurine, azathioprine, cicophosphamide (cyclophosphamide), nitrofurantoin (furadonin), furazolidone, hexamethonium benzenesulfonate (benzohexonium), propranolol (anaprilin), hydralazine (apressin), chlorpropamide, benzylpenicillin, penicillamine).