GI complaints, red urine may aid acute hepatic porphyria diagnosis
Physicians describe case of woman, 25, with gastrointestinal problems
Abdominal pain accompanied by nausea and vomiting, and a red-brownish urine could be indicative of acute hepatic porphyria (AHP), a case report suggests.
The symptoms’ presence means physicians should “consider the rare diagnosis of porphyria so that appropriate and timely treatment can be rendered and genetic screening of family members can be offered,” the authors wrote in the report, “Finding the Needle in a Haystack: Acute Intermittent Porphyria,” which was published as a letter to the editor in The American Journal of Medicine.
Porphyria is a rare genetic disease where there is a deficiency in one of the enzymes required for producing heme, a molecule needed for red blood cells to carry oxygen. AHP encompasses four different types of acute porphyrias, one of which is acute intermittent porphyria. In it, disruptions in heme production lead to heme precursors, such as porphobilinogen (PBG) building up in the liver, which can cause abdominal pain and sometimes neurological changes. Because AHP symptoms overlap with those of other diseases, diagnosing the condition can sometimes be challenging.
Leaning into diagnosis of AHP
Here, physicians in Singapore describe the case of a 25-year-old woman whose gastrointestinal complaints were likely the result of AHP.
The woman was admitted to the emergency room due to sudden stomach discomfort, nausea, and vomiting. She had severe pain, along with chest discomfort, and a history of superior mesenteric artery syndrome, where the first part of the small intestine, or duodenum, is compressed between two major blood vessels. This can cause nausea, vomiting, abdominal pain, weight loss, and malnutrition.
A physical exam was normal, but blood work revealed low potassium levels, called hypokalemia; ketoacidosis, which is a metabolic state wherein high levels of acids called ketones are produced as a result of breaking down fats; and an increase in the concentration of cells in the blood.
Her symptoms resolved after a sugar and electrolyte infusion, along with treatment with metoclopramide (sold as Reglan and others) and ondansetron (available as generics). Metoclopramide is used in gastrointestinal disorders to promote gastrointestinal movement, while ondansetron is used to prevent nausea and vomiting.
The woman had had a similar episode of acute abdominal pain and vomiting three years earlier that brought her to a gastroenterologist. Exams conducted at the time led to a diagnosis of superior mesenteric artery syndrome. Her symptoms had resolved after similar treatment.
During her recent hospitalization, physicians asked the woman about the color of her urine, which she said was reddish-brown. Further tests revealed elevated levels of PBG in the urine, supporting a possible diagnosis of porphyria. The woman declined further follow-up with a blood specialist, including a genetic analysis, which precluded confirming the diagnosis.
While her clinical symptoms might be due to superior mesenteric artery syndrome, the absence of sudden weight loss and the color of her urine, along with the fact that her symptoms eased after ingesting carbohydrates, supported an AHP diagnosis, the authors said.
“As physicians, when managing a patient with seemingly unexplained neurovisceral … symptoms, it is essential to consider the rare diagnosis of porphyria,” they wrote.
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