Pouring vinegar over jellyfish stings might worsen patients' condition, Australian researchers have found.

Vinegar is currently recommended as a first-aid treatment for jellyfish stings in Australia and the U.S. The latest study by researchers at James Cook University found that vinegar might do more harm than good.

The study findings apply to stings of several kinds of jellyfish including the deadly box jellyfish.

Box jellyfish venom is considered  one of the most dangerous venoms in the world. It has toxins that damage the heart, nervous system and skin. These organisms have dart-like structures called nematocysts on their tentacles. Contact with these tentacles leaves whip like marks on the human victim. Box jellyfish attacks are quite rare.

The Australian Resuscitation Council (ARC), which is a voluntary body representing groups associated with resuscitation, says that vinegar or 4-6 percent of acetic acid can be used as a first-aid option. Vinegar doesn't stop the pain, but slows down the discharge of venom from nematocysts.

However, the present study found that vinegar might do just the opposite.

Experiments in the lab show that vinegar releases discharge of venom. According to Dr Mark Little from JCU and Cairns Hospital, it might be time to reevaluate current first aid recommendations for Australian jellyfish stings.

"Our research findings raise concerns that vinegar has the potential to do harm when used as first aid to treat box jellyfish stings," venom expert, Jamie Seymour at the Australian Institute of Tropical Health & Medicine (AITHM) said.

"After being stung by a box jellyfish medical aid should be given immediately, with prolonged CPR to maximise the chance of survival," said Associate Professor Seymour, according to a news release.

Queensland Emergency Medicine Research Foundation funded the study and it was published in the Diving and Hyperbaric Medicine.