8. Ulceration of the Trachea by Mustard Gas
The characteristic feature is the sloughing of the tracheal mucous membrane. The reddening of the base of the tongue, and the pharynx, with a sharp delimitation where the oesophagus has refused ingress to the toxic vapour, occurs also in the case of poisoning by chlorine and the other lung irritant gases. But the pharyngeal inflammation with mustard gas may proceed further to a local ulceration that will cause dysphagia for many days.
The mucous membrane of the trachea and bronchi is affected by mustard gas in much the same way as the skin. It reacts with an intense inflammation, and death of the surface layers soon results. The mass of necrotic tissue, exuded fibrin, and pus cells may form a yellowish-grey slough in which secondary infections can flourish. Subsequently this false membrane comes away in patches or in entire casts from the raw surface of the bronchial wall.
Meantime the infected debris and secretions tend to accumulate in the bronchial ramifications at the bases of the lungs, and infection may spread from them into the lung alveoli and tissues. Septic broncho-pneumonia, localized abscesses, superficial pleurisy, and even empyema or pyo-pneumothorax then develop and cause death.
The drawing is of a trachea on the twelfth day after gassing. The base of the tongue, and the pharynx, show characteristic inflammation. Yellow necrotic sloughs lie on the larynx and at the bifurcation of the trachea. Between these the trachea is red and glistening, because it is now completely denuded of both mucous membrane and of slough. The trachea and bronchi contained an abundance of thin yellow pus.