Acute intermittent porphyria (AIP)--an unusual cause of acute confusional state. A case report.

Acute intermittent porphyria (AIP) presenting as acute confusional state without the classical features of recurrent abdominal pain, constipation, vomiting is uncommon. Such presentation in a young Malay man after a mild upper respiratory tract infection is reported. This is the first case of AIP with psychiatric symptomatology to be reported locally. The subsequent neuropsychiatric changes and interesting EEG changes are briefly discussed.