Corrosives

Mechanism of toxicity
Toxic dose
Symptoms and signs of acute poisoning
Special investigations
Management
Symptomatic and supporting
Monitoring

If uncertain whether the ingested substance is a corrosive or irritant, phone a toxicology centre.

Mechanism of toxicity

Corrosives are chemicals (primarily acids and alkalis) that cause tissue injury similar to a burn. Acids cause coagulation necrosis with eschar formation which limits penetration and depth of injury. Alkalis cause liquefaction necrosis and penetrate more deeply. Some corrosives can cause severe systemic toxicity and profound electrolyte disturbances.

Toxic dose

Determined by the corrosive concentration, pH, the site of exposure and volume ingested.

Symptoms and signs of acute poisoning

Symptoms and signs usually appear within minutes and up to 12 hours after exposure and are usually confined to the gastrointestinal tract.

• Gastrointestinal: chemical burns of oral cavity (lips, tongue, oral mucosa, oropharynx, oesophagus, or gastric mucosa) with associated nausea and vomiting, epigastria pain, dysphagia or odynophagia.
• Significant injury: airway compromise or gastrointestinal perforation complicated by peritonitis, mediastinitis, infection, sepsis and shock.

Special investigations

• Guided by symptoms and signs.
• Endoscopy indicated within 24-48 hours for severe or deliberate ingestions.

Management

Note general principles of acute poisoning

• Consider small amounts (125-250 mls) of milk or water orally to dilute corrosive.
• Neutralisation with proton pump inhibitors or H2-receptor antagonists, not shown to reduce injury.
• Prophylactic use of steroids and antibiotics not recommended.

Symptomatic and supportive

• Abdominal pain: consider antacids, proton pump inhibitors or H2-receptor antagonists; opioids
• Hypotension: IV fluids, dopamine, noradrenaline, correct metabolic acidosis.

Monitoring

• Respiratory compromise: arterial blood gas, CXR.
• Gastrointestinal complications.