To highlight diagnostic and therapeutic challenges in patients with severe porphyric neuropathy.

Acute Intermittent Porphyria (AIP) is a rare genetic disorder that leads to the accumulation of toxic metabolites as a result of an enzyme deficiency in the heme biosynthesis pathway. AIP can present with non-specific neurovisceral symptoms and motor weakness that mimics other neurologic disorders including acute inflammatory demyelinating polyneuropathy, vasculitic neuropathy, and lead toxicity. A severe AIP flare can lead to flaccid quadriplegia, respiratory paralysis, and death. While strategies and a novel therapy for preventing recurrent attacks are well-known, no guidelines exist for monitoring treatment response or disease progression in severe porphyric neuropathy.

Case series of patients with severe porphyric neuropathy

We describe two patients, one with known AIP, who initially presented to our hospital with non-specific symptoms. Each went on to develop severe motor weakness resulting in flaccid paralysis with bulbar involvement, and in one case, respiratory failure and death. The rapid progression of weakness in both cases led to concern for acute motor axonal neuropathy.  One patient received extensive immunotherapy prior to diagnosis of AIP. Challenges faced in the management of both patients included delays in treatment related to the turnaround time of special laboratory studies, limited availability of intravenous hemin due to the high cost, and lack of treatment guidelines for duration of hemin in severely affected patients.

Severe porphyric neuropathy can present as flaccid quadriplegia with bulbar symptoms. Though early diagnosis of an AIP flare may be challenging in these patients, recognition of the underlying condition and quick initiation of hemin may limit long-term disability and mortality.