Toxicology – Caustic Ingestion: Acidic Agents

Sources

Common acidic caustic substances include:

• Battery acid
• Rust removers
• Toilet bowl cleaners
• Metal and brick cleaners
• Other strong industrial or household acids

Typical Presentation

A child or adult with an acid ingestion may develop:

• Burning mouth or throat pain
• Drooling
• Painful swallowing
• Vomiting
• Chest or abdominal pain

Severe cases may progress to airway compromise or gastrointestinal perforation.

Clinical Features

Possible findings include:

• Oral burns
• Drooling
• Nausea and vomiting
• Hematemesis
• Dysphagia
• Odynophagia
• Dyspnea
• Chest pain
• Abdominal pain

Serious systemic complications can include:

• Hemolysis
• Metabolic acidosis
• Acute kidney injury
• Shock

Endoscopy may show patchy or “skip” areas of injury, so visible damage may not be continuous.

Mechanism of Action

Acids cause coagulative necrosis.

This leads to protein denaturation and formation of an eschar, which may limit deeper penetration to some extent compared with strong alkalis, although severe injury can still occur.

Management

Treatment is mainly supportive:

• Assess and protect the airway
• Monitor cardiovascular status
• Evaluate for perforation and major GI injury
• Check relevant laboratory studies in significant exposures
• Use imaging when perforation or other complications are suspected

Endoscopy is often performed in selected symptomatic patients after stabilization to determine the extent of injury.

Avoid:

• Inducing vomiting
• Gastric lavage
• Activated charcoal
• Attempting to neutralize the acid with an alkali

Neutralization can generate heat and worsen tissue injury.

Routine dilution with milk or water is not generally recommended without poison-center or specialist guidance, particularly once symptoms are present.

Key Points

• Acids classically cause coagulative necrosis with eschar formation.
• Severe injury can involve the esophagus, stomach, airway, and surrounding tissues.
• Do not induce emesis or attempt chemical neutralization.
• A relatively normal oral examination does not exclude serious internal injury.
• Airway compromise, perforation, acidosis, hemolysis, and renal injury are major complications.
• Corticosteroids are not routinely used solely to prevent strictures; their role depends on the specific clinical situation.