Combined Ethylene Glycol Poisoning with Methemoglobinemia Due to Antifreeze Ingestion

Antifreeze poisoning is potentially life-threatening and often requires multiple antidotal therapies and hemodialysis. Ethylene or propylene glycol toxicity is commonly caused by antifreeze ingestion. However, ingestion of antifreeze is typically not associated with methemoglobinemia. Currently, only one other case of antifreeze ingestion causing combined ethylene glycol poisoning and methemoglobinemia has been reported. A 56-year-old man presented after a witnessed, intentional, large-volume antifreeze ingestion. Evaluation revealed dark brown blood and significantly elevated methemoglobin and ethylene glycol levels. He was successfully treated with methylene blue, fomepizole, and hemodialysis. No other potential cause for methemoglobinemia was elucidated, and further research indicated that minor components of the specific antifreeze product served as an oxidizing agent. This case highlights the impact of minor, unreported product components that may significantly contribute to clinical toxicity, as well as the need to remain vigilant when reviewing product information and potential limitations therein.