Acute Intermittent Porphyria (AIP)

• Symptoms began several days after she decreased caloric intake to lose weight
• Drinking 48 to 60 oz of water per day for several days before admission to ameliorate constipation
• Admitted to drinking alcohol the night before pain began
• No known history of diarrhea, rectal bleeding, melena, or dysuria
• Last menstrual period ended 3 days before presentation
• Visited several other EDs before admission and had been sent home with instructions to manage constipation at home

• Consider the following:
  • Intestinal obstruction
  • Peptic ulcer disease
  • Diabetic ketoacidosis
    • Because she is an adolescent girl, it is also important to consider ectopic pregnancy and obtain a urine pregnancy test, even if the adolescent denies previous sexual activity
• Less common causes of acute abdominal pain in adolescents include pancreatitis, acute cholecystitis, intra-abdominal abscess, abdominal migraine, poisoning, and acute porphyrias

• Standard workup for patients with abdominal pain consists of:
  • Complete blood cell count
  • Electrolytes
  • Renal function tests
  • Liver function tests
  • Lipase
    • Most patients should also get a urinalysis, and girls of reproductive age should receive a urine pregnancy test
• Depending on the history and physical examination, abdominal imaging (including radiograph, ultrasound, or computed tomographic scan) may be needed
• Pelvic examination should be considered for all female patients depending on the location and quality of their abdominal pain

Test Results

• Complete blood count, liver function tests, and lipase were all within normal limits
• She was found to have hyponatremia with a sodium level of 122, but her serum urea nitrogen level, creatinine level, and other electrolyte levels were normal
• Initial urinalysis showed a specific gravity of 1.008 and was otherwise unremarkable
• Urine pregnancy test result was negative
• Abdominal radiograph showed nonspecific gaseous distension of the colon and moderate stool
• Admitted to the general pediatrics service for bowel cleanout and pain control

• Constipation and drinking a significant amount of water may be the cause of the patient’s abdominal pain and hyponatremia respectively, but it is important to consider other diagnoses
• She was not symptomatic from the hyponatremia; therefore, it could be because of a more chronic etiology

Resolution of hyponatremia and constipation

• Hyponatremia was corrected
• Once hyponatremia resolved, she successfully underwent a bowel cleanout
• Despite adequate treatment of her constipation, including a follow-up radiograph showing resolution of stool burden, the patient continues to have significant abdominal pain

• The home, education, activities, drugs, sex, suicide, and safety assessment revealed several stressors, including a recent suicide in the family and a history of disordered eating and anxiety

• Although it is rare, her constellation of symptoms (hyponatremia, abdominal pain, and psychiatric symptoms in an adolescent girl) may be caused by AIP
• Quantitative urine porphobilinogen (PBG) was sent and came back elevated at 284.6 mmol/L (normal 0–8 mmol/L), which is suggestive of AIP
• Pediatric hematology was consulted – After further questioning, the family history was notable for psychiatric illness in several other members of the family
• The patient stated that she had always had “dark urine”