Jellyfish

First aid for most jellyfish stings is to pour large amounts of vinegar over the affected area. This prevents any undischarged nematocysts (stinging cells) on the tentacles from firing more venom into the victim. Vinegar does not decrease pain or diminish the effects of the venom. Vinegar is not recommended for bluebottle (Portuguese man-o'-war) stings and may have little effect on irukandji stings. Bluebottle, irukandji, box jellyfish and Chiropsalmus quadrigata, stings have specific treatments recommended.

Box jellyfish or sea wasp (Chironex fleckeri) Domestic vinegar (never methylated spirit or alcohol) should be poured liberally over the adhering tentacles as soon as possible. Tentacular material may then be removed. Artificial respiration and cardiac massage may be required. Try and get the patient transported to an appropriate medical facility as soon as possible.

A box jellyfish antivenom is available and is recommended for all but minor stings. Specific indications include cardiorespiratory arrest or cardiac arrythmias, difficulty with breathing, speech or swallowing, severe pain, extensive skin lesions, or skin lesions in cosmetically important areas such as face, neck, hands and forearms. 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.

Chiropsalmus quadrigata Box jellyfish antivenom has been shown experimentally to neutralize Chiropsalmus venom, but clinical experience is lacking.

Irukandji (Carukia barnesi) First aid consists of analgesia and reassurance. The role of vinegar to inactivate undischarged nematocysts remains uncertain as initial work provied inconclusive. Irukandji sting victims frequently require hospitalization for analgesia and sometimes intravenous antihypertensive therapy; alpha-blocking agents such as phentolamine have been used for this purpose. Cardiac arrhythmias and cardiac failure may also require treatment, including inotropic support. No definitive treatment is currently available for Irukandji syndrome.

Bluebottle or Portuguese man-o'-war (Physalia sp.) First aid consists of removal of the tentacles, preferably with forceps. Vinegar is not recommended. Analgesia may be required, although most stings respond to ice packs and/or topical anaesthetic agents.

Other types of jellyfish Vinegar is suitable for most other types of stings. Local pain is usually best treated with ice packs. Analgesia may be required.