Teen girl’s eating disorder, cannabis use complicate AIP diagnosis
Report: Vomiting, stomach pain should cause clinicians to consider porphyria
The difficulty of diagnosing acute intermittent porphyria (AIP) due to its overlap of symptoms of other conditions, such as chronic cannabis use or eating disorders, was shown in a recent case report about a 15-year-old girl.
The girl arrived at the hospital with severe vomiting, stomach pain, and psychiatric symptoms, and was eventually diagnosed with AIP. The researchers said doctors should strongly consider AIP when a patient has unexplained severe vomiting and stomach pain, especially if they also have high blood pressure, low sodium, or constipation.
The report, “An Adolescent Female With Disordered Eating and Cannabis Use Found to Have Acute Intermittent Porphyria,” was published in Case Reports in Psychiatry.
AIP is the most prevalent type of acute porphyria, and arises due to mutations in the HMBS gene that lead to a deficiency in an enzyme needed for producing heme, which is crucial for red blood cells to transport oxygen. In the enzyme’s absence, toxic levels of heme precursors, such as porphobilinogen (PBG) and delta-aminolevulinic acid (ALA), build up, giving rise to various symptoms.
People with AIP often have episodes of severe abdominal pain, although discomfort can occur in the neck, arms, or legs. Gastrointestinal problems are frequently reported, and some may have numbness, tingling sensations, pain, and muscle weakness due to peripheral neuropathy, which affects the nerves outside the brain and spinal cord. The overlap of AIP symptoms with those of other conditions complicates a diagnosis.
Symptoms delay diagnosis
The young girl went to the emergency room with abdominal pain and vomiting lasting for six days. She hadn’t had a bowel movement since her symptoms began, but an ultrasound ruled out any intestinal obstruction. The teen had lost 8 pounds in just a week and had elevated blood pressure.
Lab work showed mildly elevated hemoglobin, low sodium levels, elevated liver enzymes, and ketones in her urine, prompting further investigation. Ketones in urine indicate the body is using fat for energy instead of sugar and indicate an underlying condition.
A urine analysis was positive for cannabinoids, the active compounds of cannabis. The girl said she had consumed cannabis every few days over the past four months. She was diagnosed with viral gastroenteritis and discharged with ondansetron for nausea. She continued using cannabis after her symptoms failed to ease, however.
The girl returned to the emergency room the following day with worsening symptoms, including seizure-like activity, confusion, and agitation.
An electroencephalogram (EEG) showed abnormal brain activity, which was later confirmed by a brain MRI. The scan revealed concerning signals across multiple brain areas. The girl was medicated with levetiracetam, an antiepileptic sold as Keppra, among others, and corticosteroids for a possible autoimmune disorder.
A psychiatric evaluation showed a history of intentional weight loss and purging behaviors that had begun about a year ago. Family members reported she had lost 35 pounds over two years, raising concerns about anorexia nervosa, an eating disorder.
Diagnosed with AIP
The girl tested negative for several autoimmune disorders. Due to her poor nutritional status and difficulty eating hospital food, a modified eating disorder protocol was started, but she was unable to adhere to it, so a nasogastric tube was placed. She was then started on total parenteral nutrition, which delivers essential nutrients directly into the bloodstream, bypassing the digestive system. The nasogastric tube had to be removed due to her anxiety, but her condition did begin to improve.
She continued to be evaluated, owing to her clinical scenario, namely her abdominal symptoms, cola-colored urine, low circulating levels of sodium, and high blood pressure. Urine tests confirmed elevated porphyrin precursors, suggesting AIP. A genetic analysis confirmed a HMBS mutation and a diagnosis.
On her 10th day of treatment, the girl began intravenous hemin therapy, which gradually improved her neurological symptoms. She became more alert and oriented in the following days, though her anxiety about hr body image and eating persisted. Hemin is essential in treating AIP because it reduces the buildup of toxic substances by restoring the heme production pathway’s balance.
The teen was discharged after 17 days with a comprehensive treatment plan, including medications for anxiety, hypertension, and seizure management, along with outpatient follow-up appointments with various specialists.
“This case represents a unique diagnostic crux in which attributing presenting symptoms to elements of the patient’s history delayed the primary diagnosis of AIP,” the researchers wrote. “Once a diagnosis of AIP is made, it is vital to perform a full psychosocial assessment that evaluates dietary habits and substance use, since these characteristics could increase the risk for future attacks, as well as any psychiatric conditions, since psychiatric manifestations of AIP are broad and more common than in the general population.”
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