Complication of smoke inhalation from fires or other noxious substances.

- Caused by heat, particulates (<1 µm diameter), or irritants (eg, NH₃) → chemical tracheobronchitis, edema, pneumonia, ARDS.- Many patients present 2° to burns, CO inhalation, cyanide poisoning, or arsenic poisoning.

- Singed nasal hairs common on exam.

- Bronchoscopy shows severe edema, congestion of bronchus, and soot deposition.