The diagnosis of porphyria often is delayed, which highlights the need for increased awareness among clinical physicians. A case report by researchers in the United Kingdom illustrates that point as it describes a patient with acute intermittent porphyria that, despite having all the classical clinical features, was diagnosed tardily.
The case study “Porphyria: often discussed but too often missed,” was published in the journal Practical Neurology. The research team also reviewed the main biological and clinical characteristics of the porphyria.
The patient, a 42-year-woman, came to the hospital due to abdominal pain and vomiting, after a three-year history of persistent daily vomiting with no identified cause. Two weeks before coming to the hospital she had traveled to Spain for holidays, and before that she started progesterone-only oral contraceptive to treat heavy menstrual periods.
Physical examination detected only mildly increased blood pressure. She was treated with fluid and Zofran (ondansetron) for the vomiting and nausea, and she was discharged.
She returned to the hospital two days later after experiencing three seizures, one of which was in the ambulance on the way to the hospital. The clinical team assumed the symptoms were due to alcohol withdrawal, although there were no basis for that assumption and she vehemently denied it.
A CT scan of her head did not reveal any anomalies, but her white blood cells were above normal, in particular the number of neutrophils was 1.7 times higher than the normal upper limit. She was treated with Pabrinex and Dilantin (phenytoin) to control seizures. Still, by day five, she had four seizures. She was referred to a seizure clinic and was discharged.
Five days later she developed severe abdominal pain and generalized discomfort, which was diagnosed as constipation due to codeine use for managing the pain.
After six days she was admitted to the hospital again with profound lack of energy that she was unable to manage at home. On examination she had increased heart rate, reduced levels of sodium in the blood, and high levels of white blood cells.
In the following days she also developed muscle pain and severe weakness affecting all four limbs. She had no movement of shoulders or elbows, and mild weakness of the wrists, as well as no movement and weakness affecting the ankles. Additional evaluations revealed she had no sensory impairment, but she had nerve cell damage.
At that point she also started to show altered behavior patterns, being persistently hypertensive and almost hysterical.
Based on the combined symptoms presentation — abdominal pain, seizures, nerve cell damage, and behavioral abnormalities — the team began to suspect she might have porphyria.
Evaluation of porphobilinogen levels — an intermediate compound of the synthesis of porphyrins — were found to be increased. A genetic analysis was performed confirming the presence of a mutation in the HMBS gene, supporting the diagnosis of acute intermittent porphyria.
She was treated accordingly with Normosang (heme arginate infusion) and her condition improved considerably, with reduced pain and better mood and muscle strength. Despite the continuous improvements, 28 months later she could walk only short distances, requiring a wheelchair for longer distances.
“Porphyria-related neuropathy [nerve damage] can be almost completely reversible if treated promptly, with most patients returning to walking within a year,” the researchers wrote.
This case highlights the importance of timely diagnosis of the porphyria. The broad and variable presentation of these disorders may represent a challenge for diagnosis, yet it is important for clinicians to pay attention and be aware of this condition.