Sea snakes (Hydrophiidae) ◦ 50 species, all toxic, 7 fatal ◦ Most bites = No Envenomation: fangs short/loose ---> poor delivery of venom Local wound care Polyvalent Sea snake antivenin
Nematocyst: spring-loaded venom glands, suddenly evert = delivering venom Tentacles are common location Functional after animal death May still be ‘loaded’ while in victim flesh ◦ Local Reaction ◦ Allergic Reaction ◦ Toxic Reaction (n/v/d, CP, cramps, SOB, paralysis, cardio-respiratory collapse)
NEMATOCYSTS BOX JELLYFISH (Sea wasp) ◦ Australia, Indian Ocean ◦ Most deadly of all E.M.L. ◦ 25% fatality rate; >sharks ◦ One BOX can kill 10 humans ◦ Cardio-respiratory arrest Occurs within minutes ◦ Medical Treatment: ABC’s Remove tentacles Vinegar Credit card scrape ANTIVENIN! (Chironex)
NEMATOCYSTS PORTUGUESE MAN-O-WAR ◦ Southern US coast ◦ Not a true jellyfish ◦ Local reaction (usually) ◦ Potential full CV collapse ◦ Several reported deaths ◦ Medical Treatment: ABC’s Remove tentacles Vinegar Credit card scrape NO Antivenin exists
NEMATOCYSTS Fire coral ◦ Worldwide reef crests & shallow waters Hawaii: conspicuously absent ◦ Local reaction Welts, redness, swelling, blisters, pus filled encystations Possible N/V up to 3 hr post Gone within 24 hr Allergic reaction(uncommon) Anaphylactic shock (rare) Infection Delayed Type IV hypersensitivity reaction
NEMATOCYSTS Medical treatment ◦ Irrigate copiously with HOT WATER; inactivates the proteinaceous toxin ◦ Vinegar ◦ Tetanus ◦ Topical anesthetics ◦ It may also ease suffering to repeatedly issue forth numerous expletives in a loud voice! ◦ Antibiotics: if infected ◦ Topical antihistamines: cortisone or Benedryl with poison ivy-like reaction
Stinger: specialized apparatus that punctures skin = delivers venom Medical Treatment: ◦ Remove stinger(s) r/o stinger in tissue with Xray ◦ Irrigate copiously with HOT WATER Hot as possible 30-90 minutes; inactivates heat labile venom ◦ Antivenin exists for Stonefish stings
STINGS STARFISH ◦ Most species non- venomous ◦ Crown-of-thorns Severe local reaction
STINGS SEA URCHINS ◦ Toxin coated spines ◦ Severity depends on species ◦ Local reaction (usually) ◦ Problem: embedded spines
STINGS STINGRAY ◦ Barbs on tail ◦ Shallow water hazard ◦ Tail spines laceration(s) ◦ Stinger Local reaction =/- systemic reaction (N/V/D, cramps, CP, SOB) Medical Treatment: stinger removal Irrigate HOT water Tetanus Antibiotics (cover vibrio)
STINGS BONY FISH (Lionfish, Stonefish) ◦ Venomous spines on fins ◦ Handled or stepped on ◦ Will attack then swim away ◦ Severe local reaction Pain, swelling ◦ Systemic reaction ◦ N/V/D, syncope, SOB, paralysis, CV collapse ◦ ANTIVENIN exists for Stonefish
44 y/o male ate seafood from a well-known, national seafood chain restaurant Presents in E.D. 2 hr after eating variety/sampler of shrimp scampi, fried shrimp, red snapper and mahi mahi C/O: N/V/D, cramps, perioral paresthesias, burning fingertips, ataxia, vertigo Exam: Ice pack to forehead, skin hot to touch, watering eyes, diaphoretic
Diagnosis? Tetrodotoxin? Why or why not How did you make the diagnosis? Medical management?
Food poisoning Allergic reaction Other diagnosis? Other ddx of ? food poisonings presenting with neurological signs/symptoms: ◦ MG, botulism, MSG, encephalitis, polio, organophosphates, anticholinergics, heavy metals, diptheria, Eaton-Lambert, plant ingestions, migraine, the bends!
Most common vertebrate fish poisoning World wide, warm water, 90% occurs in spring/summer months >500 species of fish but ALL ARE LARGE ◦ Red snapper, seabass, baracuda, grouper, kingfish, sturgeon, parrot fish
Ciguatoxin ◦ Algae/protozoa…….small fish…….large fish ◦ Heat stable; cooking does NOT kill ◦ Binds Na+ channels & increases permeability ◦ Variable toxins thus variable symptoms ◦ Ciguatoxin can be assayed (? can our lab) ◦ Toxin is absorbed quickly thus ONSET of symptoms is 1 -6 hrs after eating
Management ◦ ABC’s (include fluid resuscitation) ◦ Activated charcoal (<2hr) ◦ Cathartics (if no diarrhea) ◦ Mannitol 1 g/kg over 30 min; decreases neurological effects of the ciguatera toxin
Any large fish (Mahi mahi, amberjack) Preventable ◦ Proper food handling Spoiled fish may have honeycombing appearance Peppery taste Bacteria converts histidine to the toxins saurine and histamine Onset signs/symptoms within minutes-hours
Presents similar to allergic reaction ◦ Diffuse erythema (face, neck, torso) may progress to urticaria ◦ Numbness, tingling, perioral burning ◦ Bronchospasm Diagnosis ◦ Increased serum or urine histamine levels ◦ Test fish NOT a fish allergy if ◦ Others having same symptoms ◦ Fish can be tested
Primary sites: ◦ Japan ◦ California ◦ Africa ◦ Australia > 100 fish species ◦ Puffer fish (FUGU) ◦ Blow fish ◦ Toad fish ◦ Balloon fish ◦ Globe fish ALSO ◦ Crab eggs ◦ Blue-ringed octopus ◦ Newts
Tetrodotoxin ◦ Heat stable ◦ Concentrated in ovary, liver, skin, intestine ◦ Be afraid of female fishy in heat! ◦ Can be assayed ◦ Blocks Na/K+ activity ◦ Blocks neuromuscular activity ◦ Onset within MINUTES of ingestion
General information ◦ Mollusks filter dinoflagellates and algae ◦ Most common during red tides (dinoflagellates go crazy) ◦ Any shellfish ingestion Clam Oyster Muscle scallops Three types ◦ Paralytic (PSP) ◦ Neurotoxic (NSP) ◦ Amnesic (ASP)
Onset <30 minutes Saxitoxin blocks Na+ voltage gated channel Neuro symptoms predominately ◦ Paresthesias, ataxia, vertigo, weakness, paralysis, cranial neuropathies, respiratory failure ◦ N/V/D/cramps LESS common, not unlikely Management ◦ Supportive ◦ Possible lavage and cathartics
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