Intermittent Acute Porphyria (IAP) is a rare hereditary metabolic disorder with heme biosynthesis disorder. Dysautonomia, peripheral neuropathy and encephalopathy may occur. Peripheral neuropathy leads to weakness that can progress to tetraparesis and respiratory impairment. The diagnosis is made by porphobilinogen and aminolevulinic acid in the urine. Sometimes the diagnosis is made late because the manifestations mimic peripheral neuropathy and abdominal pain of another origin.
Case report series
Patient 1: Female, 26 years old, family history of death due to respiratory failure, started with abdominal pain and vomiting. There was rapid evolution with hyponatremia, flaccid tetraparesis and respiratory impairment undergoing mechanical ventilation. Neuroimaging, CSF analysis and screening for neuropathies were normal. Electroneuromyography showed axonal motor sensory polyneuropathy. After presumptive diagnosis of Guillain-Barré Syndrome, she was treated with 2 immunoglobulin cycles without improvement. After further clinical investigation, the diagnosis of IAP was made.
Patient 2: Male, 34 years old, presented with abdominal pain associated with constipation. After diagnosis of appendicitis, the patient underwent appendectomy without improvement. The patient evolved with tetraparesis, bladder dysfunction and respiratory impairment requiring mechanical ventilation. After change in urine color was tested and confirmed the hypothesis of IAP.
Patient 3: Female, 25 years old, presented with abdominal pain, tetraparesis and seizure. She was hospitalized after respiratory impairment. A review of family history found that her aunt had the diagnosis of Porphyria. After laboratory tests the same diagnosis was confirmed for the case.