Thallium Poisoning

Abstract

In five patients thallium intoxication was proven by urinary analysis; all had neurologic symptoms, varying from mild peripheral neuropathy to irreversible coma and death. Alopecia occurred in four of the five. Three patients had autonomic dysfunction with tachycardia and hypertension. A sural nerve biopsy in one case showed both axonal degeneration and segmental demyelination. Treatment with orally administered potassium chloride effectively releases tissue thallium but aggravates symptoms by increasing plasma thallium content. Alopecia is a relatively late manifestation of thallium poisoning, occurring three weeks after ingestion in our patients. A high index of suspicion and a simple urinary screening test can lead to a rapid diagnosis. Effective legislation could prevent this unnecessary public hazard.