Case series of Thermopsis exposures

Thermopsis species have been suspected of causing livestock losses. One human case series of Thermopsis poisoning was located in the literature. We report 23 suspected cases of Thermopsis exposures, some resulting in significant toxicity..

Retrospective chart review of all calls involving "buffalo beans" received by the Regional Poison Centre from 1990-1995.

There was a total of 23 exposures, 21 of which involved children < 12 years of age. Amounts ingested varied as did the plant part ingested. Eighteen of the patients developed symptoms within a few hours and symptoms lasted up to 12 hours. Symptoms included vomiting (14), dizziness (5), abdominal pain (3), drowsiness (2), nausea (2), headache (1), oral irritation (1), tachycardia (1), tremors (1), and other general signs (3). Of the 23 cases, 15 were managed at home but eight were referred to a health care facility, with two requiring admission. In one of the admissions, laboratory data revealed an elevated creatine kinase which remained elevated for 48 hours. Management was symptomatic and included decontamination, fluids, and observation. Plants were not professionally identified, but were referred to by the name "buffalo bean" or "buffalo pea." However, in some cases, relying on the name "buffalo bean" lead to misidentification of the plant and possible underestimation of toxicity.

Ingestion of Thermopsis can be associated with significant morbidity. Gastric lavage may be of value in large ingestions prior to symptoms but effectiveness of activated charcoal is questionable. Patients should be observed for several hours for symptoms and supportive treatment instituted as required.