Neurotoxic shellfish poisoning

Background

• Associated with red tide
• Seen in Southeast US, Gulf of Mexico, Caribbean, New Zealand
• Caused by brevetoxins secreted by dinoflagellates during algal blooms, which are then ingested by shellfish and/or aerosolized

Diagnosis

• Based on symptoms and history of ingesting shellfish or proximity to red tide

• If Ingested
  • Similar to ciguatera
  • GI symptoms - vomiting, diarrhea, abdominal cramping; usually within 30 minutes to 3 hours of ingestion
  • Neurologic symptoms - parethesias, dizziness, ataxia. Can also see hot/cold temperature sensation reversal

• If Inhaled
  • Upper respiratory tract irritation, rhinorrhea, bronchoconstriction
  • Generally affects patients with chronic respiratory disease (ie asthma/COPD)

Differential Diagnosis

Marine toxins, envenomations, and bites

• Toxins
  • Ciguatera
  • Scombroid
  • Tetrodotoxin (e.g. pufferfish)
  • Shellfish poisoning
    • Amnesic shellfish poisoning
    • Diarrheal shellfish poisoning
    • Neurotoxic shellfish poisoning
    • Paralytic shellfish poisoning
• Stingers
  • Stingray injury
• Venomous fish
  • Cone shell
  • Lionfish
  • Sea urchins
  • Crown-of-Thorns Starfish
  • Stonefish
  • Other: Catfish, zebrafish, scorpion fish
• Nematocysts
  • Coral reef
  • Fire coral
  • Jellyfish (Cnidaria)
    • Box jellyfish
      • Irukandji syndrome
    • Sea wasp
  • Portuguese man-of-war
  • Sea anemones
  • Seabather's eruption
• Phylum porifera (sponges)
• Bites
  • Alligator and crocodile attacks
  • Octopus bite
  • Shark bite
• Infections
  • Vibrio species in saltwater
  • Aeromonas species in freshwater

Treatment

• Symptomatic

Prognosis

• Most patients fully recover within 72 hours

See Also

• Marine toxins and envenomations