Acute Porphyria Screening Protocol in the Emergency Department: A Strategy for Early Diagnosis

Abstract

Acute porphyrias are a group of rare metabolic diseases, arise from defects in the heme biosynthesis pathway. These conditions are clinically characterized by acute neurovisceral attacks, chronic symptoms, and long-term complications. Given the non-specific presentation and the typically low index of clinical suspicion, diagnostic delays are recurrent and result in significant preventable morbimortality. To address and mitigate this clinical impact, a structured and clinically feasible screening protocol for the early detection of acute porphyria is herein proposed for implementation in the Emergency Department (ED), as this setting represents the principal point of care for patients experiencing an acute attack. The target population encompasses patients presenting to the ED with unexplained acute abdominal pain, acute or subacute polyneuropathy, or acute psychosis (specifically first episodes, atypical presentations, or treatment-refractory cases). Given the lack of immediate access to quantitative biochemical testing of porphyrins in the emergency setting, the Hoesch test emerges as a crucial tool. This method is a rapid, low-cost qualitative assay for detecting elevated urinary porphobilinogen (PBG), a hallmark of most acute porphyria attacks. Notwithstanding its inherent limitations, such as the potential for false negatives in the rarest subtype of acute porphyria and its reliance on operator proficiency, the systematic implementation of this Hoesch-based screening protocol offers an essential strategic approach to optimize the early recognition of acute porphyria and ultimately re duce the associated morbimortality stemming from delayed diagnosis.