I caught a deadly infection from sleeping with my dog that's left me disfigured

A man who suffered a bite from his dog contracted the life-threatening infection sepsis and has been left permanently disfigured.

The man, from Australia, was asleep in his bed when his dog laid down next to him. Not knowing his dog was there, the anonymous man rolled over and accidentally punched his dog in the face.

Startled, the pet bit his owner on wrist.

Though he thought nothing of the bite at first, he went to his local urgent care three days later after his arm became swollen and covered in red, coin-sized pustules.

He then was admitted to the hospital. Not long after that, his blood pressure dropped to 53/30, dangerously low compared to healthy pressure of 120/80.

Low blood pressure means there is less oxygen in the blood, and if left untreated, the condition can cause vital organs like the heart and brain to die.

Doctors found the man was suffering from necrotizing fasciitis, also known as 'flesh-eating disease,' a severe bacterial infection that spreads quickly and kills healthy tissues.

As the disease destroyed his tissues and infiltrated his bloodstream, it caused sepsis, a life-threatening overreaction to an infection that causes blood pressure to plummet and the immune system to attack healthy organs and tissues.

The low blood pressure deprives tissues and organs of oxygen, causing them to fail and die.

It's unclear what bacteria exactly caused the infection, but doctors told the man it 'lives on human skin.'

About 1,000 species of bacteria are naturally found on human skin and are generally harmless. The most common are Staphylococcus aureus (staph) and Streptococcus pyogenes (strep), which live inside the nose and on the skin of between 10 and 30 percent of Americans.

Doctors treating the man estimated there was just a one in 10,000 chance the bacteria would enter his bloodstream through an opening like a dog bite.

The man wrote in a Reddit post: '[Doctors] told me that it was almost certainly not from his mouth but from my skin.'

Group A Streptococcus (GAS) bacteria is the most common cause of necrotizing fasciitis, in which bacteria eats at skin, muscle and tissue until they shrivel up and die.

It kills about one in five patients.

The man said: 'I knew as soon as I woke up and looked at my arm that I was in a lot of trouble. I'm lucky I woke up in time, if I'd stayed asleep I wouldn't be here.'

His arm had turned 'bright red' and tripled in size. It was also covered in coin-sized pustules. Despite the alarming appearance, he only had minimal pain that felt like a sunburn, though he was also dizzy and nauseous.

The bacteria entering the man's bloodstream triggered a whole-body immune reaction, called sepsis, which affects 350,000 Americans every year and kills one every 90 seconds.

Sepsis is usually treated with antibiotics for the underlying infection and medications called vasopressors, which divert blood flow back to vital organs.

However, this takes blood from 'non-vital' areas like limbs, increasing the risk of tissue death and amputations. This is why the man's blood pressure dropped dangerously low.

After being rushed into surgery, doctors managed to save his arm, 'although it was close going,' he said.

Though the infection didn't reach the bone, in the past four years, he's undergone 20 surgeries to remove dead tissue, graft skin from other parts of his body on to the affected arm and reconstruct his hip and Achilles tendon due to long-term damage from the infection.

He said his arm has regained 'about 90 percent function,' but he needs regular monitoring due to lasting organ damage from the sepsis.

The man said: 'We're still trying to quantify exactly how bad the damage is, but at this stage I'm pretty optimistic. My final liver scan is this Friday, my kidneys appear to be ok, heart only took minor damage, brain is still a question.

'I'm slower than I was, and struggling with memory a bit, but I'm still pretty medicated.'

The man said his treatment totaled $500,000 AUD ($325,000 USD), but because Australia has universal healthcare, he only paid about $1,000 AUD ($650 USD).

Though the dog bite triggered the cascade of events, the man doesn't blame his pup, Scotty, and still has him.

The man said: 'He's kept me company, and sane, through all of this.

'Animals don't intend to hurt people, they just sometimes do.'

He urged people who suffer deep wounds like his to 'immediately clean, disinfect and dress it once you've stemmed the bleeding.'

He added: 'Get your backside to a medical professional ASAP. I waited a day because my regular doctor was booked out for the day.

'I should have gone straight to an [emergency department] or urgent care and gotten antibiotics.'