A child with acute respiratory distress showing hyperinflation of unilateral lung in X-ray is due to-

D i.e. Foreign body aspiration Guys if you go through this cha you can easily rule out first two options of pneumonia & now you are left with other two; in which you need a little bit of knowledge about congenital lobar emphysema Congenital Lobar Emphysema Due to dysplastic or deficient bronchial cailage or/ & bronchial compression d/ t aberrant pulmonary aery 1/ t distal lobe go into emphysematous condition. Most commonly found in infants and presents with progressive respiratory distress + progressive cynosis within first 6 months of lifeQ. Radiological - Left upper lobe > Right middle lobe involvement Hazy mass like opacity immediately after bih (d/t delayed clearance of lung fluid in affected lobe) Air trapping and hyperlucent expanded lobeQ (after clearing of fluid) which will later on cause compression collapse of adjacent lobe & opposite mediastinal shift.