Duquesne's sign, also called Duquesne's syndrome or distal pulmonary infiltration, is one of the most common symptoms observed in patients with asthma. This symptom is characterized by a percussion breath sound in the lower parts of the chest, which is a sign of dullness. On a radiograph, this symptom manifests itself as an intensification and blurring of the pulmonary pattern with the presence of nodular shadows in the lower lobes of the lungs. Duquesne's symptom is caused by swelling of the alveoli caused by blockage of the aerodynamic resistance of the airways. It can occur in varying degrees of severity and with widely variable manifestations, depending on the etiology and stage of development of the pathology. Duquesne's symptom may be accompanied by other more severe manifestations of emphysema, such as arterial