Skip to Main Content

+

  • • Acute porphyrias are a group of inherited diseased that arise from errors in heme biosynthesis leading to overproduction of a porphyrin species

    • Acute intermittent porphyria has the most serious consequences and is the form in which patients commonly manifest an acute abdomen

    • Classic patient is a young woman (teens to early 20s) with an unexplained abdominal crisis

    • Abdominal symptoms are thought to be due to acute (abdominal visceral) autonomic dysfunction

    • Acute peripheral or CNS dysfunction

    • Recurrent psychiatric illnesses

    • Hyponatremia

    • Porphobilinogen in the urine during acute attacks

++

Epidemiology

+

  • • Acute intermittent porphyria is inherited in an autosomal dominant fashion, although the trait remains clinically silent in the majority of carriers

    • Acquired forms of porphyria disorders may be caused by chemicals, drugs, or heavy metals such as lead

    • Acute porphyria may be precipitated by starvation or certain drugs, classically the barbiturates, anticonvulsants, and sulfonamides

++

Symptoms and Signs

+

  • • Absence of fever

    • Intermittent abdominal pain of varying severity, from mild colic to an acute abdomen

    • Central, peripheral, or autonomic neuropathy which can be profound including: respiratory paralysis, quadriplegia, or seizures

    • Recurrent psychiatric illness

++

Laboratory Findings

+

  • • Absence of leukocytosis

    • Often a profound hyponatremia secondary to syndrome of inappropriate antidiuretic hormone (SIADH)

    • Increased amount of porphobilinogen in the urine (freshly voided specimen may turn dark when exposed to bright light and room air)

++

Imaging Findings

+

  • • No radiographic abnormalities

+

  • • The differential diagnosis is that of an acute abdomen:

    • -Appendicitis

      -Perforated gastroduodenal ulcers

      -Diverticulitis

      -Gangrenous cholecystitis

      -Acute salpingitis

      -Nonvascular small bowel perforation

      -Large bowel perforation

      -Mesenteric ischemia

      -Acute necrotizing pancreatitis

      -Bowel obstruction

      -Incarcerated hernia

      -Ureteral or renal colic

      -Others

++

Rule Out

+

  • • Surgical abdomen

+

  • • CBC

    • Basic chemistries

    • Amylase and lipase

    • UA

    • Urine porphobilinogen

    • Abdominal pelvic CT scan with IV and PO contrast helpful in ruling out surgical etiology

++

When to Admit

+

  • • Patients with an episode of acute intermittent porphyria should be admitted for supportive medical management until attack resolves

++

When to Refer

+

  • • Acute porphyria attacks are best managed by hematologists

    • ICU care may be indicated based on severity of attack and associated neuropathy

+

  • • IV glucose (a minimum of 300 g carbohydrate per day)

    • Hematin administration

    • Analgesics

    • Correction of hyponatremia

    • Treatment as indicated for associated neuropathy

++

Surgery

+

  • • Laparoscopy

++

Indications

+

  • • In confusing cases, a diagnostic laparoscopy may exclude an abdominal surgical catastrophe

++

Medications

+

  • • Carbohydrates

    • Hematin

++

Complications

+

  • • Most common complications are related to the associated neuropathy

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.