Needle in a Haystack: Acute Intermittent Porphyria, an Often-missed Differential Diagnosis of Abdominal Pain.

Acute intermittent porphyria (AIP) is a rare disease that arises due to deficiency of the biosynthetic enzyme porphobilinogen deaminase (PBGD) involved in heme synthesis. Acute attacks can present with abdominal pain and neurological symptoms, although vague in nature. Recurrent hospitalizations for idiopathic intermittent abdominal pain should warrant investigation for AIP. Posterior reversible encephalopathy (PRES) presents with visual disturbances and seizure-like activity and can be, although rarely, associated with AIP. It is noteworthy to know that antiepileptic medication used in management of PRES can in turn worsen AIP.