Warning as Aussies return from Bali with mystery scars: 'Years to heal'

Australian tourists in Bali are being warned to protect themselves from an exotic insect that is toxic to humans.

It comes as some travellers return home from the popular holiday destination suffering strange burn-like blisters on their bodies that are taking weeks to heal.

Their painful liquid-filled blisters are being caused by a rove beetle, similar in size to an ant - known in Indonesia as tomcats.

Left: A photo of tomcat burn on woman's leg. Right: A typical rove beetle on sand
An Aussie woman vented her frustration about how slow her wound was healing. Source: Source: Facebook/C. Lewis/Getty Images

Tourist's plea for help

One Tomcat victim took to social media seeking help to heal a rash, which mysteriously appeared on her leg while she was staying in Sanur.

"Would love to know other people's experience who have been burnt by a tomcat insect in Bali and if their burn mark completely healed?" the Australian woman posted to Facebook group Bali Bogans.

The woman explained she was injured almost two weeks ago and has been using a doctor-prescribed cortisone cream on the blisters twice a day.

"Even though the burn has mostly peeled, I'm still left with burnt looking skin underneath," she wrote.

"Would love to know of anything to put on it to help because everything I'd usually use on a burn is just flaring it up again!"

Rove beetle from Bali under microscope
Australian tourists in Bali are waking up with irritating rashes caused by beetles. Source: Getty Images

Shock at bug discovery

The woman's post, which included a shocking image of her three inflamed marks, sparked fear and confusion among fellow Bali travellers.

"Never in 50 years heard of this," one man commented.

"What is a tomcat? A male cat or something Balinese please?" questioned another.

Another woman declared: "You just helped me figure out how I got my burns in Bali six weeks ago."

Rash slow to heal

Those who had previously come in contact with the poisonous insect revealed their wounds were very slow to heal.

"Seven weeks and counting. Mine was quite bad. Now just looks like a bruise. No treatment once the inflammation went down," one man wrote.

Images of tomcat burns some Australian tourists suffered in Bali
Fellow Australian tourists shared similar images of tomcat blisters they suffered while in Bali. Source: Facebook

"Yes it takes a couple of years but it does heal and my scars have gone," a woman commented.

Another woman said she still has visible marks almost two years after encountering a tomcat while in Bali.

"I call it my Bali tattoo," she wrote.

Some suggested using aloe vera and vitamin E oil to help it heal.

What causes the blisters?

Dr Swaid Abdullah, an expert in Veterinary Parasitology, explained to Yahoo News Australia that the injuries were not inflicted by a bite or sting.

"These beetles carry a toxic venom called Paederin, which causes paederus dermatitis," Dr Abdullah said.

"The toxin is spread by the beetles if they crawl on you or on your clothes, bedding or towels and can cause mild to severe skin irritation when the toxin comes in contact with the skin.

"Initial symptoms include reddening of the skin, and a 'burning' sensation. This is followed by painful irritation and itching, and if untreated can lead to extensive pustules and blistering of the skin after four days.

"The affected areas remain irritated, blistered and sore for 10 days if left unattended."

The small insect, which is commonly black and brown in colour, thrives in tropical climates during rainy seasons and has become more prevalent in Bali in recent years.

But Dr Abdullah warned they are also common on the east coast of Australia.

"It usually lives near drainage lines and watercourses. During heavy rains or floods, the beetle may migrate to drier areas," he said.

What to do if you find a tomcat

Dr Abdullah urged anyone who comes across a tomcat not to "crush" and "kill" it as you might to other bugs.

"If we crush the beetle the toxin is released and absorbed by our skin," he explained.

But if the tomcat bug does touch your skin, he said to wash the affected area immediately with soapy water.

Crowds of tourists at Seminyak Beach, Bali
As Indonesia's tourism sector picks up after the height of the Covid-19 pandemic, reports of tomcat blisters are becoming more common. Source: Getty Images

"This can help since the toxin penetrates the skin slowly. Washing immediately after exposure can help remove much of the toxin before it has time to harm the skin," he said.

"Afterwards, use cold wet compresses and seek medical help if it gets worse."

Dr Abdullah said insecticides can be used to kill the bugs but warned they can still cause symptoms when dead.

He pointed to NSW Health guidelines, which recommend wearing long-sleeved and long-legged clothing to minimise skin exposure and to check areas for beetles before going to bed.

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