Venomous Creatures – Jellyfish Stings

Jellyfish belong to the phylum Cnidaria, which is defined by a unique venom delivery system. Cnidae (nematocysts) are small cells that are attached via tentacles in jellyfish and when triggered, either mechanically or chemically fire a small barb loaded with venom that embeds into victims. Nematocysts, and the venom they contain, are the primary cause of morbidity from jellyfish stings in humans.

In humans, activated nematocysts remain within the victims’ skin and continue injecting venom. Unfired nematocysts will remain on tentacles attached to skin and can fire at a later time after further mechanical or chemical stimulation. Therefore, careful management of jellyfish exposure is crucial to minimize additional nematocyst discharge and further venom delivery.

This article reviews the general approach to jellyfish stings, including guidelines for pre-hospital management, ED management, and species-specific symptoms and management.

PRE-HOSPITAL MANAGEMENT

All jellyfish sting victims should be removed from the water. Intact species or tentacles should be handled carefully to avoid harming any rescuers or bystanders. Any life-threatening symptoms should be addressed with basic life support measures. Further management varies by species, but the following basic principles apply (1):

1. Stabilize undischarged nematocysts

2. Remove intact species/tentacles

3. Deactivate venom

4. Control pain

Step 1 – Stabilizing Undischarged Nematocysts

In general, stings in tropical waters are managed with topical vinegar, which is thought to stabilize undischarged nematocysts. Some in vitro studies (2) have demonstrated increased nematocyst discharge with vinegar application. However, conflicting in vivo studies (3) have led the American Red Cross to phase out this recommendation in favor of topical lidocaine (4). In Australia, this recommendation stands for tropical waters. Non-tropical jellyfish stings are managed with seawater rinses for nematocyst stabilization.

Step 2 – Removal of Intact Species and Tentacles

The easiest way to remove tentacles is by rinsing with sea water. If unsuccessful, further tentacle removal should be done carefully with gloved hands and tweezers. For some species, you can apply shaving cream or a slurry of baking soda and shave off the remaining nematocysts with a razor or credit card.

Step 3 – Venom Deactivation

Some species, such as the Australian Box Jellyfish (Chironex fleckeri), have a specific antivenom that should be given as soon as possible after a sting, as exposures can cause rapid-onset systemic symptoms and death. Other species deliver heat-labile venom that causes extreme pain and local skin necrosis. Heat-labile venom can be deactivated by hot water immersion (5).  

Step 4 – Pain Control

Most of the pain from a sting is caused by the toxins in jellyfish venom, therefore pain management is primarily achieved by venom deactivation. To augment pain control in the pre-hospital setting, topical lidocaine and ice (or cold packs) are recommended (6). Once in the hospital, additional parenteral analgesia may be required.

Official Guidelines for First Aid of Jellyfish Stings

AHA = American Heart Association (7), ARC = American Red Cross (4), AuRC = Australian Resuscitation Council (8)

EMERGENCY DEPARTMENT MANAGEMENT

The steps of pre-hospital management will likely continue in the ED – namely stabilization of nematocysts, venom deactivation, removal of tentacles and pain control. ED care should also involve local wound care and the consideration of tetanus and antibiotics.

Wound care will involve hemostasis, foreign body removal, irrigation, and wound closure. Patients should be up to date with tetanus vaccination. Antibiotics covering Vibrio species should be considered for grossly contaminated wounds.

SPECIES-SPECIFIC PRESENTATION AND TREATMENT

Scyphozoans (True Jellyfish)

• Mauve Stinger (Pelagia Noctiluca)
  • Presentation: stinging pain, erythema, edema, vesicles
  • Treatment:
    • Ice packs for pain
    • NO VINEGAR

• Atlantic Sea Nettle (Chrysaora Quinquecirrha)
  • Presentation: erythema and pink spots
  • Treatment:
    • Baking soda slurry to stabilize undischarged nematocysts
    • Lidocaine for pain relief
    • NO VINEGAR

• Lion’s Mane Jellyfish (Cyanea Capillata)
  • Presentation:
    • Local: pain, swelling, erythematous stripes
    • Systemic: nausea, sweating, cramping
  • Treatment:
    • Baking soda slurry to stabilize undischarged nematocysts
    • Hot water or ice packs for pain
    • NO VINEGAR

• Thimble Jellyfish (Linuche Unguiculata)
  • Presentation: Seabather’s eruption – vesicular/morbilliform pruritic dermatitis in swimsuit distribution from jellyfish larvae trapped on the suit
  • Treatment:
    • Baking soda slurry
    • Calamine lotion w/menthol

Cubozoa (Box Jellyfish)

• Australian Box Jellyfish (Chironex fleckeri)
  • Presentation:
    • Local: painful wheals and vesicles progressing to blisters and necrosis
    • Systemic: muscle spasms, hemolysis, acute renal failure, transient followed by rapid hypotension, dysrhythmias leading to cardiac arrest, pulmonary edema
    • Severity is related to size of jellyfish and extent of tentacle contact
    • Children are more vulnerable
  • Prehospital:
    • Antivenom STAT (if available)
    • Vinegar to stabilize undischarged nematocysts
    • Cold packs for pain
  • Emergency Department:
    • NO HOT WATER
    • Antivenom
      • Initial: 1 vial IV/IO or 3 vials IM
        • Repeat q10min x 3 prn
      • If peri-arrest (coma, dysrhythmia, respiratory depression): 3 vials
      • If cardiorespiratory arrest: 6 vials
      • Maintenance: 1 ampule q2-4hrs
      • Not available in US
    • Analgesia
    • Cardiorespiratory support
    • Consider magnesium

• Hawaiian Box Jellyfish (Carybdea Alata)
  • Presentation:
    • Local: painful wheals and vesicles
    • Systemic: possible Irukandji syndrome (see below)
  • Treatment:
    • Hot water immersion
    • Analgesia
    • Cardiorespiratory support

• Irukandji jellyfish (Carukia Barnesi and others)
  • “Irukandji” is the name of the indigenous tribe that inhabited coastal regions around Cairns and noted that entering the water at certain times of the year caused symptoms consistent with what is currently referred to as Irukandji syndrome (9)
  • Venom: catecholamine release, vasoconstriction
  • Presentation:
    • Local: mild transient pain at sting site, erythema, papules
    • Latent period: 25-40 min
    • Systemic: severe pain, muscle spasms, hypertension, intracranial hemorrhage, tachycardia, profuse sweating, stress cardiomyopathy leading to pulmonary edema
  • Diagnostics: troponin, ECG
  • Prehospital
    • Vinegar to stabilize undischarged nematocysts
    • Hot shower or ice packs for pain relief
    • Cardiopulmonary monitoring
  • Emergency Department:
    • Hot water immersion for venom deactivation and pain control
    • Analgesia
    • Blood pressure support (avoid beta-blockers)
    • Magnesium (if refractory hypertension)
      • Loading dose: 10 mmol
      • Maintenance dose: 5 mmol/hr x20 hr
    • Calcium for muscle spasms
    • Cardiorespiratory support

Hydrozoans

• Physalia (Portuguese man-of-war and bluebottle)
  • Physalia Physalis (Portuguese Man O’ War – Atlantic, larger, more tentacles)

• • Physalia Utriculus (bluebottle jellyfish – Pacific, smaller, fewer tentacles)

• • Venom: hemolysis, mast cell degranulation, vasodilation of skeletal muscle, blocks glutamate receptors, stimulates smooth muscle
  • Presentation:
    • Local: intense pain, skin irritation leading to necrosis
    • Systemic: anaphylaxis, nausea/vomiting, muscle spasms, altered mental status, syncope, cardiac dysrhythmias, hypotension, respiratory failure
  • Prehospital (10):
    • Nematocyst stabilization: lidocaine, “Sting No More”, baking soda, consider vinegar (controversial)
    • Pain relief: hot shower, lidocaine, Stingose (aluminum sulfate), consider ice (controversial)
    • Cardiorespiratory monitoring
  • Emergency Department
    • Hot water immersion, consider cold packs for pain relief (controversial)
    • Tentacle removal (if not done in field)
    • Analgesia
    • Antihistamines
    • Corticosteroids (if severe)
    • Cardiorespiratory support

• Fire coral (Millepora)
  • Presentation: burning pain, papules, urticarial wheals
  • Treatment:
    • Vinegar
    • Antihistamines
    • Steroid cream
    • Analgesia

Anthozoa (Sea Anemone)

• Venom: cytolytic, hemolytic, neurotoxin, cardiotoxin, proteinase inhibitors
• Presentation:
  • Local: erythema, pruritis, blisters that lead to hemorrhage/necrosis
  • Systemic: fever, chills, malaise, weakness, nausea/vomiting, muscle spasms, syncope
• Treatment:
  • Vinegar
  • Antihistamines
  • Analgesia

Species-Specific Treatments

More articles in the Venomous Creatures series here: Wilderness Medicine

Resources:

1. Lakkins NA, Maalouf GJ, Mahmassani DM.  Jellyfish Stings: A Practical Approach. Wilderness and Environmental Medicine.  2015;26:422-429.
2. Birsa LM, Verity PG, Lee RF.  Evaluation of the effects of various chemicals on discharge of and pain caused by jellyfish nematocysts.  Comparative Biochemistry and Physiology, Part C.  2010;151:426-430.
3. Ward, NT, Darracq MA, Tomaszewski C, Clark RF.  Evidence-Based Treatment of Jellyfish Stings in North America and Hawaii.  Annals of Emergency Medicine.  2012;60(4):399-414.
4. American Red Cross Scientific Advisory Council.  2016. Jellyfish Stings.  
5. Atkinson PRT, Boyle A, HArtin D, McAuley D.  Is hot water immersion an effective treatment for marine envenomation?  Emerg Med J.  2006;23:503-508
6. Wilcox CL, Yanagihara AA.  Heated Debates: Hot-Water Immersion or Ice Packs as First Aid for Cnidarian Envenomations?  Toxins.  2016;8(97).
7. Markenson D, Ferguson JD, Chameides L, Cassan P, Chung K-L, Epstein J, Gonzales L, Herrington RA, Pellegrino JL, Ratcliff N, Singer A. Part 17: first aid: 2010 American Heart Association and American Red Cross Guidelines for First Aid. Circulation. 2010;122(suppl 3):S934 –S946.
8. Australian Resuscitation Council.  2010. Envenomation – Jellyfish Stings.  Guideline 9.4.5.
9. Carrette TJ, Underwood AH, Seymour JE. Irukandji syndrome: A widely misunderstood and poorly researched tropical marine envenoming. Diving and Hyperbaric Medicine. 2012;42(4):214-223.
10. Wilcox CL, Headlam JK, Doyle TK, Yanagihara AA.  Assessing the Efficacy of First-Aid Measures in Physalia sp. Envenomation, Using Solution and Blood Agarose-Based Models.  Toxins.  2017;9(149).
11. Auerbach PS, ed. Wilderness Medicine. 6thed. Philadelphia, PA: Mosby, Inc; 2012:1628-1645.
12. Balhara KS, Stolbach A.  Marine Envenomations. Emerg Med Clin N Am.  2014;32:223-243.
13. Cegolon L, Heymann WC, Lange JH, Mastrangelo G.  Jellyfish Stings and Their Management: A Review. Marine Drugs.  2013;11:523-550.
14. Fernandez I, Valladolid G, Varon J, Sternbach G.  Encounters with Venomous Sea LIfe. The Journal of Emergency Medicine.  2011;40(1):103-112.
15.  Hornbeak KB, Auerbach, PS.  Marine Envenomation. Emerg Med Clin N Am.  2017;35:321-337.
16. Li L, McGee RG, Isbister GK, Webster AC.  Interventions for the symptoms and signs resulting from jellyfish stings.  Cochrane Database of Systematic Reviews.  2013;12:CD009688.
17. Montgomery L, Seys J, Mees J.  To Pee, or Not to Pee: A Review on Envenomation and Treatment in European Jellyfish Species.  Marine Drugs.  2016;14:127.
18. Tibballs, J.  Australian venomous jellyfish, envenomation syndromes, toxins and therapy.  Toxicon.  2006;48:830-859.

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