TOXICOLOGY

First aid for jellyfish stings: Do we really knowwhat we are doing?Mark LittleDepartment of Emergency Medicine, Caboolture Hospital, Caboolture, Queensland, Australia

Abstract

Jellyfish stings remains a common envenoming, and yet confusion appears to exist in thecommunity as to the correct first aid. Current guidelines from the Australian ResuscitationCouncil still recommends ice for most jellyfish stiings, although there appears to belittleevidence to support this. There is more evidence supporting the use of hot water. Moreresearch is required to simplify first aid for jellyfish stings.

Key words: first aid, hot water, ice, jellyfish.

A ‘stinger’ season has passed since Loten et al.1 pub-lished their randomized trial (a rarity in toxicology)comparing ice packs with hot water immersion (at 45°C)to treat patients stung by Physalia sp. (Bluebottles orPortuguese man-of-war). The many hundreds of peoplestung by Physalia sp. on south-eastern Queenslandbeaches in the 2006/2007 summer were still beingtreated with ice packs. They were following guidelinesas recommended by the Australian ResuscitationCouncil (ARC).2

The ARC gives separate advice for tropical and non-tropical stings, and recommends vinegar for tropicaljellyfish stings, and the application of cold packs orwrapped ice pain relief for all jellyfish stings. For non-tropical blue bottle, stings, the ARC now recommendsrinsing the area with sea water and placing the stungarea in hot water. If the pain is unrelieved or hot wateris unavailable, ice is recommended. Despite theserecommendations, a prospective study of 107 patientsstung by jellyfish contacting the Western AustralianPoison Information Centre found 12 different first aid

treatments were used.3,4 This suggests that recom-mended first aid treatments might not be effective,and/or there is confusion about the most appropriateone to use.

Vinegar has been demonstrated to prevent nemato-cysts firing in laboratory Chironex fleckeri (the ‘Boxjellyfish’) models.5 However, vinegar will not have aneffect on the nematocysts that have fired or the venomreleased, and will only prevent further undischargednematocysts from firing. Currently, it is recommendedand routinely used for first aid treatment in C. fleckeristings to prevent life-threatening envenoming. It isassumed that it might be effective for other types of boxjellyfish, and is also recommended for Irukandji syn-drome. Vinegar might precipitate nematocyst firingwith Chrysaora quinquecirrha (American sea nettle)6

and some other types of jellyfish, so it is not recom-mended for other types of jellyfish.

The evidence for ice being recommended as a first aidfor pain in jellyfish stings appears to be based on oneuncontrolled study of 143 patients stung by Physalia on

Correspondence: Dr, Mark Little, Emergency Physician and Clinical Toxicologist, Director, Department of Emergency Medicine,Caboolture Hospital, Caboolture, Qld 4510, Australia. Email: mark_little@health.qld.gov.au

Mark Little, FACEM MPH&TM, DTM&H.

doi: 10.1111/j.1742-6723.2007.01053.xEmergency Medicine Australasia (2008) 20, 78–80

© 2008 The AuthorJournal compilation © 2008 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine

six beaches in Queensland.7 A prospective study of boxjellyfish stings over 13 years from the Northern Terri-tory also reported the use of ice packs.8 In this series of225 stings, Currie and Jacups report 129/181 (71%)patients stung having ice applied. However, analgesiawas also administered to 108 of these patients, of which68 required opiate analgesia, suggesting that ice alonewas not effective. In the study by Loten et al.,1 at 10 min32% of those receiving ice packs had clinicallyimproved pain, which did not increase after 20 min.However, 53% of those receiving hot water immersionhad clinically improved pain at 10 min, which increasedto 87% at 20 min. This suggests that the ice might besimply a placebo effect as discussed by Loten et al.1

Hot water immersion, heat therapy and hot showershave been tested in a number of studies. Bowra et al.9

studied 54 patients in a randomized controlled trial inSydney of hot showers versus ice packs, and showed asignificant reduction in pain and duration of treatmentwith hot showers compared with ice packs. A smallstudy from Busselton demonstrated a significant reduc-tion in pain with the use of heat compared to ice.10 Anumber of studies in Hawaii of the box jellyfish supportheat therapy for stings by these jellyfish,11–13 including acontrolled study in volunteers comparing heat, papainand vinegar,12 and a randomized trial comparing hotand cold packs.13 Although there were some method-ological problems with these studies, they all suggestedthat hot water treatment was effective for relieving pain.This was also supported by animal studies whichshowed that heat inactivated venom from a range ofjellyfish.14 The most recent study by Loten et al. pro-vides more definitive evidence that hot water immersionis effective.1

There have been theoretical concerns that heat mightenhance C. fleckeri venom absorption which has beenexaggerated in the popular press.15 Currently, a random-ized controlled trial comparing ice and hot water immer-sion for box jellyfish stings is being conducted todetermine if hot water immersion is also effective forC. fleckeri stings (Geoff Isbister, pers. comm.)

There continues to be confusion about the appropri-ate first aid for most jellyfish envenomings in Australiaand the world. Patients will often not know what jelly-fish has stung them, so first aid needs to be simple,easily understood and performed. Vinegar preventsnematocysts from firing but does nothing to affect thevenom that has been released. This is recommended forbox jellyfish, but further work to confirm if it is effectivefor all jellyfish stings is required. There is very littleevidence to support the use of ice packs for jellyfish

stings, and there is increasing evidence that hot waterimmersion is more effective in reducing the pain ofjellyfish stings. It is time that bodies, such as the ARC,recommend the first aid treatment supported by theevidence. Because many beaches will not have a ther-mometer to accurately test the water temperature, anyrecommendations for jellyfish stings should be as forstings by fish, that the water is ‘no hotter than thevictim can comfortably tolerate’.16 Hopefully, the rela-tively cheap installation of thermostatic mixing valveswill be undertaken in beach first aid stations aroundAustralia to allow an accurate supply of water at 45°C.

Accepted 29 August 2007

References

1. Loten C, Stokes B, Worsley D et al. A randomised trial of hotwater (45C) immersion versus ice packs for pain relief in blue-bottle stings. Med. J. Aust. 2006; 184: 329–30.

2. Australian Resuscitation Council. Guideline 8.9.6. Envenomation– Jellyfish stings. Australian Resuscitation Council guidelines,July 2007.

3. Forbes R, Little M, Lynch D et al. Epidemiology of jellyfish stingsreported to the Western Australian Poisons Information Centre.ACEM Tasmania Faculty Scientific Meeting April 2005.

4. Pereira P, Carrette T, Cullen P et al. Pressure immobilisationbandages in the first aid treatment of jellyfish envenomation.Current recommendations reconsidered. Med. J. Aust. 2000; 173:650–2.

5. Hartwick R, Callanan V, Williamson J. Disarming the box jelly-fish. Med. J. Aust. 1980; 1: 15–20.

6. Burnett JW, Rubinstein H, Calton GJ. First aid for jellyfishenvenomation. South. Med. J. 1983; 76: 870–2.

7. Exton DR, Fenner PJ, Williamson J. Cold packs: effective topicalanalgesia in the treatment of painful stings by physalia and otherjellyfish. Med. J. Aust. 1989; 151: 625–6.

8. Currie BJ, Jacups SP. Prospective study of Chironex fleckeri andother box jellyfish stings in the ‘Top End’ of Australia’s NorthernTerritory. Med. J. Aust. 2005; 183: 631–6.

9. Bowra J, Gillet M, Morgan J et al. A trial comparing hot showersand icepack in the treatment of physalia envenomation[Abstract]. Emerg. Med. 2002; 14: A22.

10. Taylor JG. Treatment of jellyfish stings. Med. J. Aust. 2007; 186:43.

11. Yoshimoto CM, Yanagihara AA. Cnidarian (coelenterate) enveno-mations in Hawaii improve following heat application. Trans. R.Soc. Trop. Med. Hyg. 2002; 96: 300–3.

12. Nomura JT, Sato RL, Ahern RM et al. A randomised pairedcomparison trial of cutaneous treatments for acute jellyfish(Carybdea alata) stings. Am. J. Emerg. Med. 2002; 20: 624–6.

13. Thomas CS, Scott SA, Galanis DJ et al. Box jellyfish (Carybdeaalata) in Waikiki: their influx cycle plus analgesic effect hot cold

First aid for jellyfish stings

79© 2008 The AuthorJournal compilation © 2008 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine

packs their stings swimmers beach: a randomised, placebo-controlled clinical trial. Hawaii Med. J. 2001; 20: 100–7.

14. Carrette T, Cullen P, Little M et al. Temperature effects on boxjellyfish venom: a possible treatment for envenomed patients?Med. J. Aust. 2002; 177: 654–5.

15. Murtagh C. Hot water sting remedy blasted. Cairns Post, 3January 2007.

16. Australian Resuscitation Council. Guideline 8.9.8. Envenomation– Fish stings. Australian Resuscitation Council guidelines,March 2001.

M Little

80 © 2008 The AuthorJournal compilation © 2008 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine