4 Jellyfish Stings

Question 1

most important groups of jelly fish affecting humans

Answer 1

Portugese man-of-war or bluebottle jellyfish
Physalia species

Indo-Pacific box jellyfish
Chironex fleckeri

Australian jellyfish
Carukia barnesi

Question 2

most universally beneficial treatment for jellyfish envenomation

Answer 2

1. irrigation with SEAWATER
   - to remove nematocysts
2. hot water immersion
3. application of topical lidocaine

Question 3

remarks of treatment of jellyfish envenomation

Answer 3

do NOT irrigate with freshwater because the hypotonic solution is thought to stimulate nematocyst discharge

Sodium bicarbonate or vinegar may worsen stinging from some species, such as Physalia stings

Question 4

most widely distributed jellyfish

Answer 4

Physalia species

“Portugese man-of-war and bluebottle jellyfish”

Question 5

remarks on the Portuguese man-of war

Answer 5

it’s technically a siphonophore (colony of specialized organisms) rather than a true jellyfish

Question 6

pattern of Physalia sting

Answer 6

“string of pearls” pattern - linear erythematous eruption

Question 7

Treatment of Physalia stings

Answer 7

1. wash the area with seawater or normal saline to remove and deactivate undischarged nematocysts
2. immerse in hot water (43.3-45.6 C), as the venom is heat labile
3. remove tentacles and nematocysts by scraping the skin with a sharp object (e.g., razor or credit card) or by applying adhesive tape
4. apply lidocaine

vinegar is NOT recommended for Physalia stings
there’s no specific antidote for Physalia envenomation

Question 8

world’s most venomous animal

Answer 8

Indo-Pacific box jellyfish (Chironex fleckeri)

-death can occur in within 1-2 minutes, likely from cardiotoxicity

Question 9

sting pattern of box jellyfish

Answer 9

pathognomonic crosshatched pattern - “frosted ladder” pattern

Question 10

condition caused by Australian jellyfish

Answer 10

Irukandji syndrome

• initially causes localized pain and erythema
• 20-30 minutes later, severe generalized pain in the abdomen, back, chest, head, limb
• systemic signs of catecholamine excess (tachycardia, htn, sweating, piloerection, agitation)
• severe cases: cardiogenic shock with pulmonary edema with troponin elevation

Australian jallyfish - Carukia barnesi

Question 11

Remarks on treatment of box jellyfish envenomation

Answer 11

1. In Indo-Pacific waters, particularly those surrounding Australia, nematocyst deactivation therapy with 5% acetic acid (Vinegar) is recomended
2. there is a sheep-derived Antivenom specific for Chironex fleckeri
   - should be administered IV ASAP
   - can be given for 3 or more doses until with clnical response
3. Magnesium should be considered in refractory cases of Chironex envenomation with cardiac arrest