Biomedical Ephemera, or: A Frog for Your Boils

Ulceration of the trachea by mustard gas.

When the mucous membrane of the trachea and bronchi is exposed to mustard gas, it reacts much the same way as the skin, with intense inflammation followed by sloughing of the necrotic tissue. The dead epithelium combined with the exuded fibrin and pus creates an ideal environment for microorganisms to flourish, and infection can be difficult to prevent, especially since a fair proportion of the debris ends up gathering at the bottom of the lungs.

Should a patient be able to avoid infection and fatal bleeding from ulcers, the raw bronchi underneath the sloughed layer often remains intensely painful upon movement for at least a week, leading to dysphagia (resistance to eating - the esophagus pushes against the trachea when food is swallowed). A nutritive liquid formula should be provided if available. 

An Atlas of Gas Poisoning. Medical Research Council, 1918.