Marine Toxicology

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Marine Toxicology

• Rob Hall PGY3 and Dr. I. Vicas
• Toxicology Rounds
• Jan 9th, 2003

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GOALS FOR TODAY

• ENVENOMATIONS
• Three mechanisms of envenomation
• Standard treatment for each mechanism
• Recognize life threatening
• MARINE FOOD POISONING
• Common causes
• Presentation, diagnosis, management!

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Not the band Venom!

• Phil
• Tony
• Robbie Drummond

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MARINE ENVENOMATIONS

• 2000 species of venemous marine animals
• General Mx
• Remove from water drowning MCC of death
• Local wound care
• ? Specific antivenom
• Be prepared to manage anaphylaxis

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Three Mechanisms of Envenomation
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BITES

• Octopi
• Local wound care irrigate, debride, dress,
  tetanus, analgesia
• Blue - ringed Octopus can be lethal (tetrodotoxin
  like venom)

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BITES

• Seasnakes
• 50 species, all toxic, 7 fatal
• Most bites do not result in envenomation b/c
  fangs short/loose ---gt poor delivery of venom
• Local wound care polyvalent sea snake antivenom

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NEMATOCYSTS

• Nematocyst spring - loaded venom gland that
  suddenly everts and delivers venom
• Often located on tentacles
• Remain functional after animals death
• May still be loadedwhen in skin
• Local reaction, allergic reaction, toxic reaction
  (N/V/D, CP, cramps, SOB, paralysis,
  cardiorespiratory collapse)

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What is a Nematocyst?
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NEMATOCYSTS

• General Mx
• Cut off tentacles
• Inactivate nematocysts VINEGAR
• Remove nematocyts credit card scrape
• Antihistamine, analgesia
• Antivenom only exists for seawasp

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NEMATOCYSTS

• Jellyfish
• Usually only local reaction
• Remove tentacle, vinegar, credit card scrape,
  antihistamine, analgesia

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NEMATOCYSTS
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NEMATOCYSTS

• Box Jellyfish (Seawasp)
• Australia, Indian ocean
• MOST deadly of all envenomating marine life
• 25 fatality rate more deaths than sharks!
• One box can kill 10 humans
• Cardioresp arrest within minutes
• Mx ABCs, remove tentacles, VINEGAR, credit card
  scrape, ANTIVENOM (Chironex)

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NEMATOCYSTS
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NEMATOCYTS

• Portuguese Man -o - war
• Southern US coast line
• Not a true jellyfish
• Usually only local reaction
• Potential for full CV collapse
• Many deaths reported
• Mx ABCs, remove tentacles, vinegar, credit card
  scrape, NO antivenom exists

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STINGS

• Stinger specialized apparatus that punctures
  skin and delivers venom
• Mx
• Remove stinger (? Xray to r/o stinger in tissue)
• Irrigate copiously, tetanus, analgesia
• HOT WATER for 30 - 90 min (inactivates the heat
  labile venom hot as possible)
• Antivenom exists for stonefish stings

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STINGS

• Starfish
• Most nonvenomous
• Crown - of - thorns severe local reaction

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STINGS

• Sea Urchins
• Toxic coated spines
• Severity depends on species
• Usually only local reaction
• Imbedded spines problematic

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STINGS

• Stingray
• Barbs on tail
• Stepped on in shallow water
• Tail spines ---gt laceration
• Stinger local /- systemic rxn (N/V/D, cramps,
  CP, SOB)
• Remove stinger, irrigate, HOT water, tetanus, abx
  to cover vibrio

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STINGS

• Bony fish (Lionfish, Stonefish)
• Venomous spins on fins
• Stepped on or handled
• Will attack b/f swimming away
• Severe local rxn pain, swelling
• Systemic rxn N/V/D, syncope, SOB, paralysis, CV
  collapse
• ANTIVENOM exists

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The Goods on Marine Envenomations
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MARINE FOOD POISONING

• Consider the patient who is sick after eating
  seafood..

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MARINE FOOD POISONING

• 30YO male at fish from BOYDS SEAFOOD on New
  Years Eve
• Presents 2hrs after eating fish (Red snapper and
  Mahi mahi)
• Nausea, vomiting, diarrhea, cramps
• Perioral peresthesias, burning fingertips,
  ataxia, vertigo, ice pack on forehead felt hot,
  watery eyes, diaphoretic

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MARINE FOOD POISONING

• What is your ddx?
• Is this tetrodotoxin..why or why not?
• How are you going to make the diagnosis?
• What is your management?

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MARINE FOOD POISONINGS

• Food Poisoning
• Allergic reaction
• Other ddx of ? Food poisoning presenting with
  neurological signs/symptoms
• MG, botulism, MSG, encephalitis, polio, tick
  paralysis, carbon monoxide, organophosphates,
  anticholinergics, heavy metals, diptheria,
  eaton-lambert, plant ingestion, migraine, the
  bends!

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FISH POISONINGS

• Ciguatera
• Scombroid
• Tetrodotoxin

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CIGUATERA

• Most common vertebrate fish poisoning
• World wide, warm waters, 90 in spring/summer
• gt 500 species of fish but ALL ARE LARGE
• red snapper, seabass, baracuda, grouper,
  kingfish, sturgeon, parrot fish

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CIGUATERA

• Ciguatoxin
• Algae/protozoa ------- small fish ----- large
  fish
• Heat stable thus cooking does NOT kill
• Binds Na channels and increases permeability
• Variable toxins thus variable symptoms
• Ciguatoxin can be assayed (? Can our lab do it)
• Toxin is absorbed quickly thus ONSET of symptoms
  is 1 6 hrs after eating

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CIGUATERA
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CIGUATERA

• Management
• ABCs (including fluid resusc)
• Activated charcoal if lt 2hrs
• Cathartics if no diarrhea
• Mannitol
• Case reports of 1 gm/kg over 30 min decreasing
  neurological effects of ciguatera

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SCOMBROID

• Any large fish (MahiMahi amberjack)
• Preventable with proper preparation
• Spoilage bacteria convert hisitidine to saurine
  and histamine which are the toxins
• Spoiled fish may have honeycombing or peppery
  taste
• Onset of symptoms within minutes - hours

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SCOMBROID

• Presentation similar to allergic reaction
• FLUSHING of face, neck, torso (diffuse erythema)
  can progress to urticaria
• Numbness, tingling, burning around mouth
• Can have bronchospasm
• Diagnosis increased histamine levels in serum
  or urine (can also test fish)
• NOT a fish allergy if others with same symptoms
  or if fish can be tested

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SCOMBROID

• Consider ddx of flushing, bronchospasm, and
  headache
• Anaphylaxis, anaphylactoid reaction, scombroid,
  MSG, tyramine, ethanol flush, tartrazine,
  metabisulfites
• Management
• Benadryl, ranitidine
• Ventolin prn
• ? Activated charcoal if early, ? Cathartic
• Epinephrine if needed

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TETRODOTOXIN

• Japan, California, Africa, Australia
• gt 100 fish
• Puffer fish (FUGU), blow fish, toad fish, balloon
  fish, globe fish
• Also crab eggs,blue-ringed octopus, newts

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TETRODOTOXIN

• Toxin
• Heat stable
• Concentrated in ovary, liver, skin, intestine
• Watch out for the female fishy in heat!!
• Can be assayed
• Blocks Na/K activity and blocks neuromuscular
  activity
• Onset within MINUTES of ingestion

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TETRODOTOXIN

• Presentation
• Headache, diaphoresis
• Paresthesias of lips, tongue, mouth, fingers/toes
• Dysphagia, dysarthria, ataxia, fasiculations
• Ascending paralysis and resp arrest
• Management
• ABCs, supportive, ? AC and cathartics, call the
  priest (mortality 50)

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SHELLFISH POISONING

• General
• Mollusks filter dynoflagellates and algae
• More common during red tides when dinoflagellates
  go crazy (can occur inbetween red tides)
• Any shellfish ingestion clam, oyster, muscle,
  scallops
• Three Patterns
• Paralytic Shellfish Poisoning (PSP)
• Neurotoxic Shellfish Poisoning (NSP)
• Amnestic Shellfish Poisoning (ASP)

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PARALYTIC SHELLFISH POISONING (PSP)

• Onset lt 30 min
• Saxitoxin blocks Na voltage gated channel
• Neuro symptoms predominate
• Paresthesias, ataxia, vertigo, weakness,
  paralysis, cranial neuropathies, resp failure
• N/V/D/cramps LESS common
• Mx
• Supportive /- lavage and cathartics

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NEUROTOXIC SHELLFISH POISONING (NSP)

• Onset ave 3hrs (15 min 18hrs)
• Toxin Brevitoxin
• GI Neuro symptoms
• GI N/V/D/cramps
• Neuro paresthesias, temp reversal, ataxia,
  vertigo, areflexia, NO paralysis
• Bradycardic and mydriasis, bronchospasm
• Mx
• Supportive, ventolin, ? decontamination

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AMNESTIC SHELLFISH POISONING (ASP)

• Onset ave 5hrs (15 min 36hrs)
• Toxin Domoic acid (Canadian outbreak 1987)
• GI Neuro CV
• GI N/V/D/cramps
• Neuro MEMORY LOSS (damage to amydala and
  hippocampus)..sz, grimacing, chewing,
  opthalmoplegia less common
• CV hypotension and arrythmias
• Mx supportive, ? decontamination

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OTHER POISONINGS

• Botulism
• Canned foods classic but can be from fresh fish
• GI neuro (diplopia, dysphagia, dysarthria,
  weakness)
• Toxin binds at NMJ
• Consider with
• Myasenia gravis, eaton lambert, tick paralysis,
  gullian barre, miller fisher syndrome

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SUMMARY of FISH POISONING
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SUMMARY of SHELL FISHINGESTION