Diagnostic Dilemmas in Acute Intermittent Porphyria
Objective: To present the importance of early diagnosis of acute intermittent porphyria (AIP) in patients with atypical presentation and discuss the diagnostic problems encountered in this case. Clinical Presentation: A 15-year-old girl presented with upper respiratory tract infection, fever, seizures and abdominal pain. An initial diagnosis of encephalitis was made. She received antiviral drugs and anticonvulsants. Two weeks later, she developed progressive flaccid quadriplegia and facial weakness. She also developed respiratory paralysis and was intubated. Cytoalbuminous dissociation was seen in the cerebrospinal fluid. A diagnosis of severe Guillain-Barré syndrome was made. Intervention: The patient received a course of intravenous immunoglobulins which did not result in any clinical improvement. Plasmapheresis, started after 12 weeks, led to partial improvement. The patient continued to have attacks of seizures, abdominal pain and vomitting with severe quadriparesis. A repeat screening test for urine porphyrins was positive, and AIP was confirmed by specific porphobilinogen deaminase in the blood. The patient was treated with large doses of intravenous glucose, followed by injections of hematin. The patient improved remarkably. She was extubated, discharged from Intensive Care Unit and started on a rehabilitation program. Conclusion: This patient was initially diagnosed erroneously with a negative screening test for AIP and consequently treated inappropriately. The proper diagnosis was made after repeating the screening test followed by specific tests of porphobilinogen deaminase.