Darkness on the edge of town: A rural family maliciously poisoined by thallium

Thallium was banned as a rodenticide in 1975. Now acute thallium poisoning is rarely seen outside of the industrial setting. A 41 year-old female was admitted to the hospital for increasing lower extremity weakness and back pain. Within 2 days, rapidly ascending paralysis and respiratory failure necessitated intubation. A 24 hour urine 13 days after admission revealed a thallium level of 5000 mcg/mL, and the serum thallium was 471 ng/mL 14 days after admission. Prussian blue (250 mg/kg/day) was administered orally for 17 days, until the serum thallium level was 41 ng/dL. Her hospital course progressed from alopecia, quadriparesis, hyporeflexia, and disconjugate gaze, to recovery of some facial muscles and diaphragm strength, but still requiring pressure support ventilation and a tracheostomy. Her 10 year-old son with reported elevated levels and peripheral neuropathy was treated with Prussian blue. Other possible victims included an 18 year-old son, a visitor with gastrointestinal symptoms and hair loss, and a visiting dog that died after a two day course of vomiting and diarrhea and the inability to ambulate. Thallium poisoning should be considered in a case of rapidly ascending paralysis. If the diagnosis is made, surveillance of associates of the patient must also be made because of the high possibility of homicide.