A 23 year old Afro-Caribbean man was brought to the accident and emergency department by his mother. He had a known diagnosis of schizophrenia, which was managed with 10 mg olanzapine once a day, but he was taking no other drugs, had no allergies, and had no other medical history. His mother said that he was normally fully oriented, independent for activities of daily living, and enjoyed attending his part time IT skills course. He was usually amiable and calm, but she had noticed a change in his behaviour over the past 12 hours. She described him as being confused and agitated. He refused to leave the house the day before and had been reluctant to come to the hospital. She confirmed that he takes his daily drugs but said that he looked “a bit shaky.”

On examination the patient was disoriented, was able to localise pain (Glasgow coma scale 13/15), and was sweating. He had a fever (38°C), tachycardia (100 beat/min), and a generalised increase in muscle tone. His urine drug screen was negative for all illicit substances and he had no history of alcohol intake. He had a raised white cell count and raised creatinine kinase (2500 IU/l; normal range in men 25-195 IU/l). No clear focus of infection was evident, and he had not recently travelled abroad.