Marine Toxicology

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

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

3. Phil Tony Robbie Drummond Not the band Venom!

4. 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

5. Three Mechanisms of Envenomation

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

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

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

9. What is a Nematocyst?

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

11. Jellyfish Usually only local reaction Remove tentacle, vinegar, credit card scrape, antihistamine, analgesia NEMATOCYSTS

12. NEMATOCYSTS

13. 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)

14. NEMATOCYSTS

15. 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

16. 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

17. Starfish Most nonvenomous Crown - of - thorns: severe local reaction STINGS

18. Sea Urchins Toxic coated spines Severity depends on species Usually only local reaction Imbedded spines problematic STINGS

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

20. 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 STINGS

21. The Goods on Marine Envenomations

22. MARINE FOOD POISONING • Consider the patient who is sick after eating seafood…………..

23. MARINE FOOD POISONING • 30YO male at fish from BOYD’S SEAFOOD on New Year’s 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

24. 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?

25. 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!

26. FISH POISONINGS • Ciguatera • Scombroid • Tetrodotoxin

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

28. 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

29. CIGUATERA

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

31. 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

32. 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

33. 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

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

35. 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

36. 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%)

37. 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)

38. PARALYTIC SHELLFISH POISONING (PSP) • Onset < 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

39. 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

40. 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

41. 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

42. SUMMARY of FISH POISONING

43. SUMMARY of SHELL FISHINGESTION