Marine Envenomatins Flashcards
Jellyfish
• Found in every ocean and coastal region. Related freshwater jellyfish don’t envenomate.
• Larvae are called “sea lice.” They lodge in bathing suits and can cause dermatitis.
• Nematocyst: (Cnidocysts, cnidoblasts) located in specialized cells in the tentacles fire out on contact to pierce
the skin and inject venom, causing immediate pain and urticarial eruption.
o Possible: Mild systemic symptoms: Nausea, headache, dizziness, sweating, lacrimation.
o Possible: Delayed hypersensitivity, poison-ivy-like reaction. (Treatment: Steroids and antihistamines.)
Jellyfish
Treatment
• First-aid goals are to deactivate unfired nematocysts on the skin and remove adherent tentacles.
o Wash with sea water (basically normal saline).
Avoid fresh water because a change in tonicity can fire the nematocysts.
No ammonia, no alcohol/beer, no urine, no sand.
Vinegar compress for 30 minutes, or paste made of meat tenderizer (papain).
Hot water or ice pack may help – experience on this is conflicting.
• Wounds occurring in water environments often get infected; antibiotic of choice is a cephalosporin.
• Tetanus prophylaxis; treat pain with topical local anesthetic and possibly NSAIDS or opiates.
Box jellyfish
“Sea Wasp”
• Australian. Very toxic, translucent blue with tentacles reaching several meters. Tentacle tracks leave long,
intensely-red lines along victim’s body. Ovine (sheep-derived) antivenin available in Australia.
o Immediate pain, paresthesia, paralysis, pruritic rash.
o Rapid cardiorespiratory depression and death within minutes; 15-20% fatality.
o Potentially fatal anaphylactoid reactions.
Irukankji syndrome
from related tiny box jellyfish
• Minimal skin signs; delayed onset systemic toxicity: Excruciating muscle cramps in back, chest, sides.
• Tachycardia, hypertension (possible intracerebral hemorrhage), sweating, nausea, vomiting, headache,
restlessness, impending doom; 30-50% incidence of cardiac insufficiency, pulmonary edema.
• Treatment includes bolus and continuous infusion of magnesium.
Portugese Man of War
(class Hydrozoa) • Tentacles can reach 8 to 10 feet. Found off the coast of Florida in the summer, and as far north as New Jersey o Do not use vinegar; it increases delivery of toxin and increases pain.
Fire Coral
Not a true coral, it is a Hydrozoa like the Man of War. Can be mistaken for seaweed. Venom
produces immediate burning pain and intense itching.
o Wash with sea water, saline, or vinegar. Steroids for intense itching.
Sponges
Animals, not plants. Contain calcium carbonate and silica spicules that enter skin and cause intense
itching, which is comparable to poison ivy.
o Remove spicules by scraping or using adhesive tape and give analgesics and diphenhydramine.
Cone Snails
Nocturnal mollusks of tropical/subtropical waters; found off southern CA.
o Peptide neurotoxin is injected from a modified tooth (“radula”) to immobilize prey. It is barbed and can
be extended some distance out from the mouth of the snail, at the end of the proboscis.
o Smaller cone snail sting is similar to bee sting. Large tropical cone snails cause intense local pain and
paresthesias, vomiting, paralysis, and respiratory failure
o Treat with local hot water immersion. Otherwise most symptoms will resolve within 8 hours
Whelks
Aggressive, carnivorous sea snails. Only a few of them use salivary-gland venom to capture prey;
most of them are non-venomous and edible.
o Whelk venom contains a tetramine salt. Consumption can cause food poisoning with eyeball pain,
headache, dizziness, nausea, and abdominal pain.
Australian blue-ringed octopus
Venom similar to tetrodotoxin in salivary glands.
o Pain, numbness, paresthesia, dysphagia, blurred vision, coma, and cardiovascular collapse.
o Treatment is supportive.
Sea Urchins
Prey is attacked with spines containing venom. Dye within the spines is blue or purple.
o Remove spines, inspect joints, (may require fluoroscopy to visualize as spines are radiopaque), hot
water immersion, antibiotics, and tetanus prophylaxis.
Stingray
• Tail barb inflicts deep trauma and injects heat-labile venom - wound severely painful.
• Systemic envenomation: Paresthesia, salivation, nausea, vomiting, diarrhea, cramps, sweating, fasciculations,
convulsions, paralysis, hypotension, respiratory depression, cardiac arrhythmia.
• Treatment: Hot water immersion, pain control, wound care, cephalosporin.
Stonefish
• Highly venomous, especially Australian. Fatality reported. Some off the coast of Florida.
• Neurotoxic venom is secreted from glands at the base of their dorsal spines, which become erect when the fish
is disturbed or threatened. Humans accidentally step on the stonefish as it lies quietly on the bottom.
• Excruciating pain with rapid onset of tremendous edema and tissue necrosis.
• Treatment: Hot water immersion. Antivenom is usually stored at marine research facilities.
Lionfish
(Pterois) same family as the stonefish; delivers venom by erect spiny fins.
• Found in salt-water hobby aquariums. Related fish include turkeyfish, zebrafish, tigerfish, and scorpion fish.
• Very painful but not life threatening. Treatment: Hot water immersion.
Weever fish
Bury themselves in sand, just showing their eyes; stepped on by unwary beach-frolickers to cause a
painful sting. Found on the European side of the Atlantic. Treatment: Hot water immersion.
