FIELD: medicine. SUBSTANCE: method involves measuring proper cell fluorescence intensity for cells taken from bronchial lavage fluid. Intracellular proper pyridine nucleotides fluorescence intensity is measured under excitation wavelength being equal to 356 nm and recording wavelength being equal to 420-480 nm. The case of flavoproteins is treated at excitation wavelength being equal to 440-480 nm and recording wavelength being equal to 510-550 nm. The ratio of intensities of the intracellular proper pyridine nucleotides and flavoproteins fluorescence is measured. The ratio being greater than 1, bronchial asthma is diagnosed. The ratio being less than 1, obliterating bronchiolitis is to be diagnosed. EFFECT: high accuracy of differential diagnosis. 1 tbl
