A 16 years old female, was referred to Pakistan Institute of medical sciences Islamabad, from a private setup in Gilgit Baltistan for management of acute abdominal pain.
She developed severe abdominal pain while on her way to the school and was perfectly alright before that. There was no history of nausea, vomiting, dyspepsia or fever associated with the abdominal pain.
On Examination …
Examination at the time of arrival was unremarkable except for diffusely tender abdomen. While she was investigated, supportive treatment in the form of intravenous fluids, proton pump inhibitors and antibiotics were started.
Laboratory Investigations …
Her laboratory investigations were unremarkable except for a White blood cell count of 11000/mcl. Her ultrasound abdomen and x-ray erect abdomen was also unremarkable.
CECT abdomen and pelvis showed non-specific mesenteric lymphadenopathy. During her stay in the hospital, she developed generalized tonic-clonic seizures. Her blood sugars and serum calcium levels were done which were normal but she had severe hyponatremia of 105 mEq/L. The neurology department was consulted and she was started on anti-epileptics. For workup of hyponatremia, a medical consult was sought.
Before going on to the workup advised by the medical team, lets scratch our heads to diagnose this patient.
- What workup may be advised at this stage?
- What is the possible diagnosis?
- How will you manage this patient?
Students should try to make a diagnosis or differential diagnosis before reading the discussion below.
Follow-up of our patient with abdominal pain…
When we first saw the patient, she was afebrile, conscious and obeying commands at that time. She had a soft and non-tender abdomen. The following things were kept in mind while we started investigating her:
- What is the cause of hyponatremia? Is it renal wasting or a gut pathology? Is it SIADH?
- What is the underlying diagnosis?
Her urinary and serum electrolytes were sent which suggested SIADH (high urinary sodium, low plasma osmolality, and high urinary osmolality. She was started on a calculated dose of hypertonic saline and free water restriction.
Since a surgical cause of the acute abdomen was ruled out, and medical causes of the acute abdomen are very few, acute intermittent porphyria was our presumptive diagnosis. The patient was asked to collect her urine and keep it in sunlight for sometimes. Her urine for porphobilinogen was also sent.
Urine color of the patient turned reddish-brown on exposure to sunlight and her urine for PBG was strongly positive as well.
She was started on dextrose water with saline and her anti-epileptics were stopped. She rapidly improved and was discharged with instructions to avoid certain medications.