Nematocysts: Difference between revisions
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==Mechanism== | ==Background== | ||
*Jellyfish; [[box jellyfish|box jellyfish]] is most deadly | |||
*Most toxic: Australia and other Indo-Pacific waters | |||
<gallery mode="packed"> | |||
File:Avispa marina cropped.png|[[Box jellyfish]] | |||
File:Lithothamnion sp..jpg|Coral reef | |||
File:Portuguese Man-O-War (Physalia physalis).jpg|Portuguese Man-O-War {Physalia physalis) | |||
File:Actiniaria.jpg|A selection of various sea anemones | |||
</gallery> | |||
===Mechanism=== | |||
[[File:Nematocyst discharge.png|thumb|Nematocyst stages of discharge]] | [[File:Nematocyst discharge.png|thumb|Nematocyst stages of discharge]] | ||
*Physical contact or osmotic gradient causes discharge of | *Physical contact or osmotic gradient causes discharge of nematocysts | ||
*A spring loaded venom delivery system | *A spring loaded venom delivery system | ||
*Once opened, a nematocyst releases all of its contained venom | |||
==Clinical Features== | |||
[[File:PMC3760923 abd-88-0496-g04.png|thumb|Skin lesion after contact with the cubomedusa Chiropsalmus quadrumanus jellyfish]] | |||
*Isolated stinging, pain | |||
*Severe | |||
**Limb [[weakness|paralysis]] | |||
**[[Respiratory arrest|Respiratory paralysis]] | |||
**[[Shock|Cardiovascular collapse]] | |||
**[[cardiac arrest|Death]] | |||
==[[Irukandji syndrome]]<ref> Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.</ref>== | |||
*Usually develops within 2 hours of envenomation & can last up to 2 days | |||
*Rare but potentially fatal complication. It often involves intense pain, diffuse muscle cramps, vasconstriction and marked hypertension due to a catacholamine surge. | |||
**Beware of [[hypertensive emergency]]: Look for signs of end organ damage (ie ACS, CHF, intracranial hemorrhage, renal injury) | |||
==Differential Diagnosis== | |||
{{Marine envenomation DDX}} | |||
==Evaluation== | |||
*Generally a clinical diagnosis | |||
==Management== | |||
*Remove tentacles and nematocysts | |||
*Hot salt water immersion (inactivates heat labile toxins), submerging the area in 45 ℃ water for 20 minutes has been shown to provide significant pain relief<ref>#Isbister GK, Currie BJ. Hot water immersion v icepacks for treating pain of Chironex fleckeri stings: a randomised controlled trial. Med J Aust. 2017 Oct 16;207(8):362. PubMed PMID: 29020913.</ref> | |||
*Stingose is a topical solution composed of 20% aluminum sulfate and 1.1% surfactant. | |||
**Used for pain control, venom removal via osmosis, & venom neutralization via denaturation of proteins and polysaccharides through interactions with the aluminum ion.<ref>Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.</ref> | |||
*Consider topical [[lidocaine]] | |||
*Consider oral or parenteral [[analgesia]] for severe pain | |||
*In general, avoid acetic acid (vinegar) since it mostly increases the firing of nematocysts and therefore increases pain.<ref>Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/. </ref> | |||
**Some evidence that it does inhibit nematocyst discharge in the Australian Box Jellyfish species <ref>Yanagihara AA, Wilcox CL. Cubozoan Sting-Site Seawater Rinse, Scraping, and Ice Can Increase Venom Load: Upending Current First Aid Recommendations. Toxins (Basel). 2017;9(3):105. Published 2017 Mar 15. doi:10.3390/toxins9030105</ref> | |||
***Box Jellyfish: 4-5% acetic acid solution should be applied to the injured area for at least 30 seconds.<ref>Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/. </ref> | |||
*Symptomatic treatment for [[Irukandji syndrome]] | |||
**Consider [[fentanyl]] for pain and antihypertensives such as magnesium sulfate and nitroglycerin | |||
*Antivenom is only readily available in Australia for severe [[box jellyfish]] sting | |||
===Avoid=== | |||
*Urine, ethanol, ammonia, | |||
*Acetic acid/vinegar (unless box jellyfish) <ref>Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/. </ref> | |||
*Fresh or tap water (causes nematocyst discharge via the osmotic gradient) | |||
==Disposition== | |||
==See Also== | |||
*[[Marine toxins and envenomations]] | |||
*[[Sea wasp]] | |||
==References== | |||
#Ward NT, Darracq MA, Tomaszewski C, et al. Evidence based treatment of jellyfish stings in North America and Hawaii. Ann Emerg Med. 2012;60(4):339-414. | |||
#Cegolon L, Heymann WC, Lange JH, et al. Jellyfish stings and their management: a review. Mar Drugs. 2013;11(2): 523-50 | |||
[[Category:Environmental]][[Category:Toxicology]] | |||
[[Category: |
Revision as of 02:40, 31 July 2021
Background
- Jellyfish; box jellyfish is most deadly
- Most toxic: Australia and other Indo-Pacific waters
Mechanism
- Physical contact or osmotic gradient causes discharge of nematocysts
- A spring loaded venom delivery system
- Once opened, a nematocyst releases all of its contained venom
Clinical Features
- Isolated stinging, pain
- Severe
Irukandji syndrome[1]
- Usually develops within 2 hours of envenomation & can last up to 2 days
- Rare but potentially fatal complication. It often involves intense pain, diffuse muscle cramps, vasconstriction and marked hypertension due to a catacholamine surge.
- Beware of hypertensive emergency: Look for signs of end organ damage (ie ACS, CHF, intracranial hemorrhage, renal injury)
Differential Diagnosis
Marine toxins, envenomations, and bites
- Toxins
- Ciguatera
- Scombroid
- Tetrodotoxin (e.g. pufferfish)
- Shellfish poisoning
- Amnesic shellfish poisoning
- Diarrheal shellfish poisoning
- Neurotoxic shellfish poisoning
- Paralytic shellfish poisoning
- Stingers
- Venomous fish
- Cone shell
- Lionfish
- Sea urchins
- Crown-of-Thorns Starfish
- Stonefish
- Other: Catfish, zebrafish, scorpion fish
- Nematocysts
- Coral reef
- Fire coral
- Jellyfish (Cnidaria)
- Portuguese man-of-war
- Sea anemones
- Seabather's eruption
- Phylum porifera (sponges)
- Bites
- Infections
Evaluation
- Generally a clinical diagnosis
Management
- Remove tentacles and nematocysts
- Hot salt water immersion (inactivates heat labile toxins), submerging the area in 45 ℃ water for 20 minutes has been shown to provide significant pain relief[2]
- Stingose is a topical solution composed of 20% aluminum sulfate and 1.1% surfactant.
- Used for pain control, venom removal via osmosis, & venom neutralization via denaturation of proteins and polysaccharides through interactions with the aluminum ion.[3]
- Consider topical lidocaine
- Consider oral or parenteral analgesia for severe pain
- In general, avoid acetic acid (vinegar) since it mostly increases the firing of nematocysts and therefore increases pain.[4]
- Symptomatic treatment for Irukandji syndrome
- Consider fentanyl for pain and antihypertensives such as magnesium sulfate and nitroglycerin
- Antivenom is only readily available in Australia for severe box jellyfish sting
Avoid
- Urine, ethanol, ammonia,
- Acetic acid/vinegar (unless box jellyfish) [7]
- Fresh or tap water (causes nematocyst discharge via the osmotic gradient)
Disposition
See Also
References
- Ward NT, Darracq MA, Tomaszewski C, et al. Evidence based treatment of jellyfish stings in North America and Hawaii. Ann Emerg Med. 2012;60(4):339-414.
- Cegolon L, Heymann WC, Lange JH, et al. Jellyfish stings and their management: a review. Mar Drugs. 2013;11(2): 523-50
- ↑ Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.
- ↑ #Isbister GK, Currie BJ. Hot water immersion v icepacks for treating pain of Chironex fleckeri stings: a randomised controlled trial. Med J Aust. 2017 Oct 16;207(8):362. PubMed PMID: 29020913.
- ↑ Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.
- ↑ Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.
- ↑ Yanagihara AA, Wilcox CL. Cubozoan Sting-Site Seawater Rinse, Scraping, and Ice Can Increase Venom Load: Upending Current First Aid Recommendations. Toxins (Basel). 2017;9(3):105. Published 2017 Mar 15. doi:10.3390/toxins9030105
- ↑ Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.
- ↑ Hauglid, C., Kiel, J., & Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/.