This case report presents a patient with ethylene glycol intoxication from antifreeze ingestion. Ethylene glycol is an active ingredient in antifreeze, traditionally causing an anion gap metabolic acidosis with a high osmolality gap. In our emergency department, serum ethylene glycol is a send-out test requiring hours for a result. The patient presented here had an initial acidotic venous blood gas with an elevated serum osmolality and osmolality gap, and a normal anion gap. Quick bedside analysis of the patient’s urine using ultraviolet fluorescence gave supportive evidence for the ingested substance while the serum ethylene glycol level was still pending. The patient was promptly treated with fomepizole, pyridoxine, thiamine, and sodium bicarbonate. Several hours after admission, the ethylene glycol level had resulted as 636 mg/dL. Due to the quick initiation of treatment, the patient had no complications or signs of end-organ damage during admission.TopicsEthylene glycol, fomepizole, toxicology, ultraviolet fluorescence.