Toxicology – Moth Repellent Poisoning

Source

Moth repellents may contain naphthalene, paradichlorobenzene, or camphor. Their toxicity varies considerably: paradichlorobenzene is generally less toxic, while camphor can cause severe neurological effects, including seizures.

Typical Presentation

A young child accidentally puts mothballs in the mouth and later develops gastrointestinal symptoms, altered mental status, or seizures. The presentation depends on the specific chemical involved.

Clinical Features

• Camphor: Nausea, vomiting, abdominal pain, headache, dizziness, confusion, seizures, coma, and possible liver injury. Symptoms may begin rapidly.
• Naphthalene: GI irritation, headache, dizziness, fever, altered mental status, and occasionally seizures. It may also cause hemolytic anemia and methemoglobinemia, especially in patients with G6PD deficiency.
• Paradichlorobenzene: Usually causes milder GI symptoms and headache after acute exposure. Repeated or prolonged exposure may lead to ataxia and encephalopathy.

Mechanism of Action

The mechanism differs according to the chemical involved. Toxic effects may include direct gastrointestinal irritation, neurological toxicity, oxidative injury to red blood cells, and impaired oxygen transport.

Management

Treatment is mainly supportive:

• Remove the patient from further exposure.
• Provide airway, breathing, and circulatory support as needed.
• Treat seizures and other complications appropriately.
• Gastrointestinal decontamination may be considered in selected recent exposures under toxicology guidance.

Key Points

• Camphor poisoning tends to cause symptoms quickly and is particularly associated with seizures.
• Naphthalene toxicity may be delayed and can cause hemolysis or methemoglobinemia.
• Patients with G6PD deficiency are at greater risk of oxidative red-cell injury from naphthalene.
• Identifying the specific moth repellent ingredient helps predict the expected toxicity.