Comment on Chronic Ciguatera Poisoning

To the Editor:

Dr. Johnson-Arbor ¹ described an illustrative case of ciguatera fish poisoning, but we disagree on treatment. Johnson-Arbor ¹ describes the evidence supporting mannitol as “minimal.” This description is subjective and misleading. In fact, mannitol is the most studied treatment for ciguatera fish poisoning (including cases involving symptoms for weeks or months). ^{2 -4}

Her patient received duloxetine and pregabalin, with no mention of whether these were effective. At best, these 2 medications each have 1 supporting case report.^5,6 Typically, treatment with medications aimed to reduce neuropathic pain has indefinite duration, and symptoms generally return on discontinuing the medication.

Several case reports illustrate successful treatment with mannitol after weeks of ciguatera symptoms. ^{7 -10} A systematic review of treatments for ciguatera fish poisoning concluded that mannitol has the best supporting evidence, although the majority of the evidence for any proposed treatment is mostly low in quality. ¹¹

Mannitol is an inexpensive medication with minimal adverse effects in otherwise healthy people. Given the potential for the significant morbidity due to chronic toxicity, we advocate for its use, especially early in the patient’s course.