An unusual cause of acute confusional state.

Her father brought this female child to the Accident and Emergency Department with history of acute confusion for paediatric assessment. The child had been agitated for the last 12 hours, was difficult to settle and kept saying, “don’t want it”. She had previously been well. On examination she was agitated, apyrexial and constantly talking with heart rate of 148/min. Her pupils were dilated but equal and sluggishly reactive. She had no neck stiffness and rest of the systemic examination was unremarkable. The main differential diagnoses at this stage were probable encephalitis and acute poisoning. Her full blood count, urea and electrolytes, liver function tests, coagulation screen, paracetamol and salicylate levels, and venous gas were all normal.