(See also General Principles of Poisoning.)
Worldwide, 80% of caustic ingestions occur in young children; these are usually accidental ingestions of small amounts and are often benign. In adults, caustic ingestions are frequently intentional ingestions of large amounts by suicidal people and are life threatening. Common sources of caustics include solid and liquid drain and toilet bowl cleaners. Industrial products are usually more concentrated than household products and thus tend to be more damaging.
Pathophysiology of Caustic Ingestion
Acids cause coagulation necrosis; an eschar forms, limiting further damage. Acids tend to affect the stomach more than the esophagus.
Alkalis cause rapid liquefaction necrosis; no eschar forms, and damage continues until the alkali is neutralized or diluted. Alkalis tend to affect the esophagus more than the stomach, but ingestion of large quantities severely affects both.
Solid products tend to leave particles that stick to and burn tissues, discouraging further ingestion and causing localized damage. Because liquid preparations do not stick, larger quantities are easily ingested, and damage may be widespread. Liquids may also be aspirated, leading to upper airway injury.
Symptoms and Signs of Caustic Ingestion
Initial symptoms of caustic ingestion include drooling and dysphagia. In severe cases, pain, vomiting, and sometimes bleeding develop immediately in the mouth, throat, chest, or abdomen. Airway burns may cause coughing, tachypnea, or stridor.
Swollen, erythematous tissue may be visible intraorally; however, caustic liquids may cause no intraoral burns despite serious injury farther down the gastrointestinal tract.
Esophageal perforation may result in mediastinitis, with severe chest pain, tachycardia, fever, tachypnea, and shock. Gastric perforation may result in peritonitis. Esophageal or gastric perforation may occur within hours, after weeks, or any time in between.
Esophageal strictures can develop over weeks, even if initial symptoms had been mild and treatment had been adequate. Strictures can result in esophageal shortening or narrowing as well as dysphagia and motility disorders.
Survivors of caustic ingestions are at higher risk for development of esophageal carcinoma.
Diagnosis of Caustic Ingestion
Endoscopy
Because the presence or absence of intraoral burns does not reliably indicate whether the esophagus and stomach are burned, meticulous endoscopy is indicated to check for the presence and severity of esophageal and gastric burns when symptoms or history suggests more than trivial ingestion. Endoscopy does not need to be done immediately; the patient should be stabilized before being considered for endoscopy.
Chest x-rays have limited sensitivity for evaluation of esophageal perforation, so a CT scan of the chest and abdomen should be done if perforation is suspected.
Treatment of Caustic Ingestion
Avoidance of gastric emptying
Sometimes dilution with oral fluids
In general, acid and alkali ingestions are treated similarly, with supportive care. (CAUTION: .)
Pearls & Pitfalls
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Dilution with milk or water is only useful in the first few minutes after ingesting a liquid caustic, but delayed dilution may be useful after ingesting a solid caustic. Dilution should be avoided if patients have nausea, drooling, stridor, or abdominal distention.
Esophageal or gastric perforation is treated with antibiotics and surgery (see Acute Perforation). IV corticosteroids and prophylactic antibiotics are not recommended. Strictures are treated with bougienage or, if they are severe or unresponsive, with esophageal bypass by colonic interposition.
Key Points
Suspect severe consequences if a large volume of a caustic or an industrial-strength caustic product is ingested.
Alkalis, by causing liquefaction, can cause damage until they are sufficiently diluted.
Consider esophageal and stomach burns and do endoscopy, even if intraoral burns are absent.
Treat perforation with antibiotics and surgery.
