Acute Intermittent Porphyria After Right Hemi-colectomy

Introduction: Acute intermittent porphyria is a rare autosomal dominant metabolic disease. It is caused by a genetic mutation that results in deficiency of porphobilinogen deaminase enzyme, the third enzyme in heme biosynthesis. Acute intermittent porphyria precipitated by surgery is very rare.

Case Presentation: We present a 24 year-old woman who developed acute intermittent porphyria five days after right hemi-colectomy. Her presentation included neuro-visceral and psychiatric manifestations, and severe hyponatremia. She received critical care symptomatic management including mechanical ventilation. The diagnosis was based on a positive urine test for porphobilinogen and confirmed by the presence of a heterozygous mutation in the hydroxyrmethylbilane synthase (HMBS) gene (c.760delC p Leu254).

Discussion: Acute intermittent porphyria is the most common and life threatining type of acute porphyrias. It is more common in women and usually presents after puberty with acute abdominal pain and diverse neuro-psychiatric manifestations that can be confused with several surgical and medical diseases. Acute intermittent porphyria after surgery is most likely due to postoperative pain and low-calorie intake. Once suspected, prompt ICU management including high calorie intake are necessary to avoid serious complications and mortality before starting definitive treatment with hematin.

Conclusion: Acute intermittent porphyria should be suspected in any patient, particularly young women, who develop diverse neuro-visceral and psychiatric manifestations and hyponatremia after surgery.