Ciguatera Poisoning

Aka: Ciguatera Poisoning, Ciguatera Toxin, Ciguatoxin

1. See Also
   1. Biological Neurotoxin
   2. Biological Toxin
   3. Foodborne Illness
2. Epidemiology
   1. Most common reported fish ingestion related Poisoning in U.S.
   2. Reaction occurs in up to 90% of Ciguatoxin ingestions
   3. Most common outbreaks
      1. Florida
      2. Hawaii
      3. West Indies
      4. Puerto Rico
      5. U.S. Virgin Islands
3. Pathophysiology
   1. Dinoflagellates (unicellular protozoa)
      1. Gambierdiscus toxicus bioaccumulates in carnivorous reef fish
   2. Reef fish ingestion results in reaction (>500 individual species have been associated)
      1. Amberjack
      2. Grouper
      3. Snapper
      4. Sturgeon
      5. King Mackerel
      6. Barracuda
      7. Moray eel
   3. Toxin
      1. Ciguatoxin is a tasteless, odorless, lipid soluble toxin
      2. Ciguatoxin is heat stable and acid-stable
      3. Ciguatoxin may be transferred via Breastmilk and placenta as well as via semen
   4. Mechanism
      1. Ciguatoxin binds to open Sodium channels on Neurons (depolarized Neurons)
      2. Results in Sodium influx into Neurons, resulting in Neuronal edema
4. Symptoms: Anticholinergic Reaction
   1. Gastrointestinal (duration 24-48 hours)
      1. Nausea or Vomiting
      2. Voluminous, watery Diarrhea
      3. Abdominal Pain and cramping
   2. Neurologic (duration days to weeks)
      1. Cold-hot Sensation reversal (Cold Allodynia)
         1. Hot feels cold and cold feels hot
         2. Occurs in 80% of cases
         3. Pathognomonic for Ciguatera Toxin
      2. Numbness or Paresthesias of hands, feet and face (Tongue, lips, throat, perioral region)
      3. Vertigo or Ataxia
      4. Weakness
      5. Myalgias
      6. Headache
      7. Seizures
   3. Cardiopulmonary changes (duration days to weeks)
      1. Bradycardia
      2. Hypotension
   4. Miscellaneous
      1. Diaphoresis
      2. Sensation of loose or painful teeth
      3. Post-coital symptoms in women (Dysuria, Dyspareunia, Pelvic Pain)
5. Labs
   1. See Unknown Ingestion
   2. Serum Electrolytes
      1. Evaluate for Electrolyte losses (related to Diarrhea)
   3. Ciguatoxin Testing (ELISA or HPLC)
      1. Confirms diagnosis, but typically delayed results
      2. Ciguatera Poisoning is a clinical diagnosis
6. Diagnostics
   1. Electrocardiogram (EKG)
7. Imaging
   1. As indicated based on presentation and differential diagnosis
8. Course
   1. Anticholinergic Symptoms within 2-6 hours after ingestion
      1. Reactions delayed up to 24 hours in some cases
   2. Symptom duration: 7 to 14 days
   3. More severe cases with prior Ciguatoxin reactions
   4. Paresthesias may persist for months
9. Management
   1. See Unknown Ingestion
   2. Consider Activated Charcoal (1 mg/kg)
      1. Consider if ingestion within prior 1-2 hours and patient alert
   3. Supportive care
   4. Antiemetics (e.g. Zofran IV)
   5. Electrolyte replacement and intravenous hydration as needed
   6. May require Vasopressors for Hypotension
   7. May require Unstable Bradycardia management
   8. Avoid Alcohol
   9. Mannitol does not appear effective in shortening course
      1. Has been used at 1 g/kg over 30-240 min
      2. Schnorf (2002) Neurology 58:873-80 [PubMed]
   10. Admission Criteria
       1. Unclear diagnosis (See Unknown Ingestion)
       2. Significant neurologic or cardiac symptoms
       3. Significant Dehydration or Electrolyte abnormalities
10. Complication
    1. Stocking-Glove distribution neuropathic pain
       1. Peripheral Neuropathy symptoms may persist for weeks after onset
       2. Medications to consider
          1. Amitriptyline 25 mg orally once to twice daily
          2. Gabapentin 300-400 mg orally three times daily (start with bedtime dosing)
          3. Pregabalin 150 mg orally twice daily
11. Prevention
    1. Avoid ingestion of large warm-water reef fish
    2. Limit intakes to small quantities
    3. Avoid ingesting internal organs of fish
    4. No food preparation method deactivate Ciguatoxin
12. References
    1. Koch and Tomaszewski (2021) Crit Dec Emerg Med 35(8): 28
    2. Perkins (2004) Am Fam Physician 69(4):885-90 [PubMed]