If the patient has a delayed sensitivity reaction steroid or antihistamine cream maybe effective.Do not apply a dressing as this can cause firing the nematocysts and promote systemic envenomation.Ice packs or hot water maybe applied – there is a current debate about which one if more effective.Vinegar Has been effective for controlling pain and stopping any further discharge from any remaining nematocysts – these should then be removed either with your own hands, credit card or sticky tape.Analgesia Initially simple paracetamol and ibuprofen may suffice but if the pain is refractory IV opiates such as morphine 0.1 mg/kg every 10 minutes should be effective.Delayed hypersensitivity reactions occur in at least 50% of patients and manifest as pruritic erythema at the original sting site and can last up to two weeks.Systemic features mentioned above in the resuscitation section.

In 25-30% of cases the tentacles are still attached

Immediate severe pain, typically lasts 8 hours with linear welts in a crosshatched pattern.It is important to continue prolonged CPR as good outcomes have been achieved If the antivenom fails, 10 mol of IV magnesium should also be given.

Cardiac arrest – undiluted antivenom should be given as a rapid push unto 6 ampoules and continue with advanced life support along usual guidelines.The classic history if of someone on the tropical waters of Australia between November and April who has immediate pain after a jellyfish sting associated with a crosshatched pattern of welts on their skin. If an arrest is going to occur it typically occurs within 5 minutes likely secondary to a cardiac toxin affecting the calcium channels. Fortunately most of the stings respond well to simple first aid and patients should be reassured. It has a ferocious reputation having been responsible for a number of deaths in Australia with the majority of recent deaths in children. The Box Jellyfish is found in the Northern waters of Australia.

Box jellyfish