Toluene toxicity presenting with hypokalemia, profound weakness and U waves in the electrocardiogram

We present the case of a 25-year-old man with progressive limb weakness. His electrocardiogram showed prominent U waves which made us consider hypokalemia. The final diagnosis was toluene intoxication with severe hypokalemia and metabolic acidosis. Intravenous potassium administration and hydration effectively corrected the electrolyte and acid-base alterations; weakness resolved and the patient was discharged. The approach to a patient with acute weakness can be challenging. This case reminds us that the electrocardiogram can be a valuable tool in the evaluation and differential diagnosis of patients presenting to the emergency department with these conditions.