230 THE LARYNX, BRONCHI AND OESOPHAGUS
The area first affected is the mouth (Fig. 118) and pharynx, and if the
substance is swallowed the middle third of the oesophagus is the most
frequently involved, although the strictures may be multiple. Spillage of the
caustic substance on to the larynx may cause oedema.
PATHOLOGY. As with burns elsewhere, the caustic burn of the oesophagus
varies in degree. It may involve only the mucous and submucous layers
which heal without stricture formation. In more severe burns, necrosis may
Fig. 117, Achalasia of the oesophagus, showing greatly dilated oesophagus.
Fig. 118. Lysol bum. The caustic stain is seen on the mouth and neck. A nasogastric tube has been
inserted for feeding.
occur in the oesophageal wall involving all coats. This may heal with fibrosis
and stricture formation, or perforation of the oesophageal wall may occur.
TREATMENT. If the substance can be identified attempts should be made to
neutralize it. Most patients will have visible burns on the lips, mouth and
pharynx. The problem is to decide whether the substance has been swallowed
or if it has all been spat out. If doubt exists then it is probably safer to perform
oesophagoscopy to see the extent of the burn if it is present. A flexible
oesophagoscope should be used in preference to the rigid one. If no burn is