Challenges in early diagnosis of methanol poisoning in the emergency room - A case report

Background. Methanol is a toxic alcohol that causes severe poisoning due to its metabolites — formic and lactic acid — which lead to metabolic acidosis with a high anion gap and toxic encephalopathy. The severity of clinical features typically manifests within 6 to 72 hours and may include seizures and altered mental status. Case report. We present the case of a 45-year-old patient, a chronic alcoholic with no significant medical history, who was admitted to the Emergency Department in a comatose state (Glasgow Coma Scale [GCS] 4), tachypneic, and following a seizure episode. The patient also had a history of a minor head trauma 24 hours prior. Laboratory results revealed severe metabolic acidosis with a high anion gap, hepatocellular injury, renal insufficiency, and elevated serum levels of amylase and lipase. Toxicology screening, including a urinary sample, ethanol measurement (0 mmol/L), and imaging (MRI), strongly suggested methanol poisoning as the likely diagnosis. The patient was transferred to the Intensive Care Unit, where hemodialysis was performed. Subsequent brain scans revealed typical methanol toxicity patterns, including symmetrical necrosis of the basal ganglia and gliosis of the occipital and optic nerves. These findings underscore the importance of not attributing a low GCS solely to ethanol abuse, highlighting the need for a broader differential diagnosis.