First aid for box jellyfish stings consists of vinegar, removal of tentaclular material and analgesia.
Signs and Symptoms
- Severe localized pain, often associated with vigorous attempts by the patient to remove the tentacles (this may make the envenomation worse by causing the discharge of further nematocysts)
- Wide (0.5 -1cm) erythematous lines where the tentacles have been in contact with the skin. These may cover a large area, an indication of severe envenomation.
- Confusion, agitation
- Unconsciousness
- Collapse with respiratory failure and/or cardiac arrest
Death can occur within 5 minutes following massive envenomation. The mechanism(s) of toxicity are poorly understood, but death is thought to be due to respiratory failure, possibly central in origin, or to direct cardiotoxicity leading to A-V conduction disturbances or to paralysis of the cardiac muscle in systole. Patients may become unconscious before they can leave the water. There have been at least 63 confirmed deaths from envenomation by Chironex fleckeri in the Indo-Pacific region. In addition to cardiotoxic and neurotoxic properties, the venom also contains dermatonecrotic components producing patches of full thickness skin necrosis that may result in severe and permanent scarring. There is also a haemolytic component in Chironex fleckeri venom, although it is of doubtful clinical significance.
Treatment
Due to the rapidity of onset of symptoms, immediate first aid is vital and cardiopulmonary resuscitation may be required. Remaining undischarged nematocysts should be inactivated with large quantities of dilute (3-5%) acetic acid (i.e., household vinegar) once the patient has been safely removed from the water. Antivenom may be administered by life saving or other paramedical personnel at the scene, via the intramuscular route, although intravenous administration is preferable if appropriately skilled personnel are available.
Antivenom
Box Jellyfish antivenom is recommended for all but minor stings. Specific indications include:
In hospital, intravenous antivenom should be administered promptly if it has not already been given or if the patient remains symptomatic. Assisted ventilation and narcotic analgesia may be required. Early administration of antivenom may result in reduced pain and decreased scarring secondary to dermatonecrosis. Box jellyfish antivenom made by CSL Ltd is ovine in origin |
Photo: R. Lowe, AVRU
|
Sequelae
Dermonecrosis is commonly seen with a box jellyfish sting. No animal or human clinical data have identified any agent to reduce long term scarring. There are some case reports of acute and long term improvement if intravenous antivenom is used but good evidence for this is lacking. Areas affected should be treated in the same way as a burn. Delayed hypersensitivity reactions occur in approximately 50% of cases and should be treated with corticosteroid cream and antihistamines.
Last updated: July 2005
