Background: Human grayanotoxin poisoning is distinctly uncommon in North America, as the predominant source of human exposure is honey made by bees pollinating rhododendron species in the Mediterranean. We present a case of confirmed grayanotoxin poisoning from honey imported from Turkey.
Case report: A 61-year-old man developed nausea, lightheadedness, and lost consciousness. Onset was 30 min after the ingestion of honey that was brought to the United States from Turkey. Emergency medical services found him bradycardic, hypotensive, and unresponsive. He was treated with atropine, saline, and oxygen, at which point his heart rate and blood pressure improved, and he regained consciousness. A similar episode several days earlier was followed by a brief unrevealing hospitalization. He was again hospitalized, and had a normal echocardiogram, telemetric monitoring, and complete laboratory studies. Grayanotoxins I and III were subsequently identified in the patient's blood, urine, and honey. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Grayanotoxins are diterpenoids found in rhododendron species, whose clinical effects span multiple organ systems including gastrointestinal, cardiac, and neurologic. Treatment is largely supportive, and a good response to atropine and intravenous fluids has been described. Laboratory confirmation of grayanotoxins is not available in a short enough turnaround time to be clinically useful during immediate management, but confirmatory testing may obviate further unnecessary evaluation. Grayanotoxins are likely to remain a rare source of poisoning in North America, but recurrent bradycardia without alternative etiology should prompt a thorough exposure history, which may reveal, as in this case, a treatable toxicologic etiology.
Keywords: Ericaceae; grayanotoxin; mad honey; poisoning; rhododendron; toxicology.
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