Exogenous allergic alveolitis in children

Hypersensitivity pneumonitis is a group of non-asthmatic allergic lung diseases caused by different allergens, with diffuse interstitial inflammation as its pathological feature. It is caused by the hypersensitivity reaction caused by inhalation of various organic dust, organic dust particles (diameter 10mu; m) containing fungal spores, bacterial products, animal proteins or insect antigens. Therefore, it is also called extrasic allergic alveolitis. It was first suggested in 1932 that the farmers' lungs were caused by exposure to moldy hay. Recently, immunological techniques have been used more widely to observe various similar diseases with different antigens and different exposures.