Seizure, abdominal pain, and urine pink in an adolescent female-what's the link?

ABSTRACT

Case Report A 17 year-old female with history of depression was transferred to the pediatric intensive care unit (PICU) from an emergency department (ED) for first time seizure and subsequent encephalopathy after five days of severe, diffuse abdominal pain and vomiting. The night prior to admission, she complained of lightheadedness and then had a witnessed generalized tonic-clonic seizure lasting 45 seconds. She initially returned to her baseline but then had three additional seizures requiring ED evaluation. She received intravenous doses of lorazepam and levetiracetam that aborted the clinical seizures. She remained encephalopathic and was orotracheally intubated for airway protection. Family denied known ingestions but reported she did vape nicotine. Urine drug screen was positive for benzodiazepines, consistent with seizure management. Cerebrospinal fluid analysis was unrevealing. Urinalysis showed moderate ketones and trace blood. Urine pregnancy test and nasopharyngeal SARS-CoV-2 polymerase chain reaction were negative. Head computerized tomography scan showed no intracranial pathology. On arrival to the PICU, the patient was afebrile, tachycardic, and hypertensive to 171/118 mmHg. She was somnolent on arrival but aroused to sternal rub without focal neurologic deficit. She presented with a Foley catheter that drained pinkorange urine. A nicardipine infusion was started given concern for the development of posterior reversible encephalopathy syndrome (PRES). Thyroid function tests were consistent with euthyroid sick syndrome. BioFire meningitis panel, plasma SARS-CoV-2 IgG, and toxicologic evaluation were all negative. Electrocardiogram showed sinus tachycardia. Magnetic resonance imaging of the brain revealed cortical and subcortical areas of diffusion restriction consistent with PRES. Ultimately, a random urine porphobilinogen and a 24-hour measurement of urine porphyrins collected on hospital day 1 were both markedly elevated. A diagnosis of Acute Intermittent Porphyria (AIP) was made. A gastrointestinal porphyria specialist was consulted and recommended monthly outpatient injections of givosiran upon hospital discharge. Discussion This case illustrates the importance of considering AIP in the differential diagnosis of new onset seizure or encephalopathy associated with hypertension, tachycardia, and abdominal pain in an adolescent. This case also adds to a small number of cases associating AIP with PRES. AIP is often viewed as an adult disease because it typically presents in the third or fourth decade of life. Timely recognition of AIP in the pediatric setting is critical to preventing delays in diagnosis, treatment, and patient education on triggers of acute attacks. AIP attacks are treated with dextrose and hemin infusions to reduce production of porphyrin precursors. Prophylactic treatment of AIP now includes givosiran, an interfering mRNA that reduces levels of intermediates in heme synthesis that are neurotoxic when elevated.