Differes from plain pneumonia because of the location of lesions.Such lesions are envolved by foci that are spread and seperated by pulmonar tissues.These tissues gather in a multiple fashion,producing more extensive lesions.It rarely comes up as a primary affection and , in majority of the cases , it`s either a complicated stange of an-already-installed infection or it develops in an organism whose general state is very precarious.It strats, in most cases , from a simple catarrh of the respiratory passages, with high temperature, fits of cold and diffuse pains in the thorax.The cough, at the beginning dry envolving to productive, with abunddant, frothy and purulent expectoration,following respiratory insufficiency.It`s suggested that precautions should be taken when the early signs appear, so that the affection will not progress to a serious stage.