Unexpected presentation of a first episode of acute hepatic porphyria (AHP) presenting with severe hyponatremia, seizure, severe rhabdomyolysis, arterial hypertension and posterior reversible encephalopathy syndrome (PRES) in a female adolescent

Background: Porphyrias are rare inherited diseases resulting from enzyme deficiencies/dysfunction or insufficient substrate processing in catalysing enzymes in the haem synthesis, predominantly affecting adult females of childbearing age. Accumulation of intermediary metabolites such as porphyrins, their precursors 5-aminolevulinic acid (ALA) and porphobilinogen (PBG) in various organs causing cytotoxic or tissue-damaging effects. Aggravating factors are fasting, alcohol, smoking, androgenic hormones, visible light/UV rays and use of porphyrinogenic medications. Acute porphyrias present with episodic, potentially life-threatening neurovisceral symptoms: abdominal pain, convulsion, autonomic hyperactivity, peripheral neuropathy and psychiatric symptoms.

Case: A girl (17y) was transferred to our PICU with hyponatremia (114mg/dl) and signs of ileus, 5 days of abdominal pain, nausea and vomiting. She was afebrile, hypertensive, tachycardic and suffered from diffuse dysesthesia. She had a history of episodic abdominal pain with nausea and weight loss for two years. Family history revealed Crohn´s disease of the father but gastroscopy and colonoscopy a year ago were normal. On admission, she presented with a generalised tonic–clonic seizure (2min). Abdominal CT showed signs of at least four entero-enteric intussusceptions but contrast material showed no bowl obstruction. Laboratory investigations revealed severe rhabdomyolysis with a creatine kinase peak of 119.451 units/L, maximal serum creatinine was 1,4mg/dl. Abdominal MRI, gastroscopy and colonoscopy were normal. Intermittent neuropsychiatric symptoms with anxiety, depression, confusion, headache and visual disturbance occurred. MRI of the brain showed a PRES. Cerebrospinal fluid assessment, urine microscopy, drug screen, metabolic/endocrinology screening, serum/liquor autoimmune diagnostic were normal. Comprehensive search for infectious causes revealed positive mycoplasma pneumoniae PCR-test. Finally, the combination of non-specific abdominal pain and neuropsychiatric symptoms led to the diagnosis of AHP with abnormally elevated levels of porphyrins and PBG in urine. Intravenous dextrose was administered to inhibit aminolevulinic acid synthase (ALAS) and to stop catabolism. Intravenous hemin was started to upregulate the excretion of ALA and PBG. After 4 days of therapy, abdominal pain resolved and blood pressure as well as her behaviour normalised. Genetic testing is pending.

Conclusion: The case illustrates the diagnostic challenges of AHP. Its overlapping symptoms with more common diseases and the extremely rare pediatric onset of AHPs lead to underdiagnosis. Treatment with porphyrinogenic medication increases the risk of potentially irreversible neurological sequelae. Therefore, pediatricians should be aware of AHPs and consider them as a differential diagnosis in children and adolescents with abdominal pain, autonomic nervous system dysfunction, and neuropsychiatric findings.

Interessenskonflikte

Keine Interessenkonflikte

Publication History

Article published online:
19 May 2025