A newborn baby almost died from a spot on the back of his head that doctors said was eczema.

When Rhian Brace’s newborn son Ernie developed a blister-like spot on his head, she never thought he’d contracted a potentially deadly virus.

Ernie showed no symptoms of being unwell. He didn’t have a temperature, his nappies remained the same and his feeding was consistent. She had been told he had eczema.

She told Yahoo7 News she thought Ernie had a reaction to something or had inherited her very sensitive skin.

It was only when further blisters developed that Rhian contacted a doctor. She thought that original diagnosis didn’t seem right.

In a lengthy Facebook post, the Doncaster, UK mum shared publicly what Ernie had been through, and how it could have been prevented.

“The only indication I had that he wasn’t well was one tiny blister like spot on the back of head, which after being bathed had popped and what can only be described as puss had come away from it, I cleaned the area and re-washed his head/hair just in case it was infectious,” she wrote.

“Three days later another four had appeared and then over night another six had made an appearance, all looking like infected blisters.”

When Ernie was seen by doctors he was rushed to hospital. He was just 14 days old at the time.

His family had to wait three days for a diagnosis: He had herpes simplex virus, otherwise known as a cold sore.

Now, as Rhian wrote, that doesn't seem too serious to adults. But to babies, it can be extremely severe or even cause death.

"It is just as deadly as meningitis in babies if not treated straight away because it starts to attack their brain, lungs and other vital organs," Rhian said.

Ernie was fitted with a long line IV, so the antibiotics could be fed straight into his system.

After two weeks, Ernie had almost finished the course of IV anti-viral medicine, but he's still got a long recovery ahead of him. He will need to take a six-month course of oral medicine at home to make sure the virus has been completed killed.

"We have been told that if Ernie gets to his first birthday and the virus has not come back or showed anymore signs then the virus that has hospitalised him for the first weeks of his life has been completely killed," Rhian wrote.

The virus Ernie was diagnosed with can be contracted via human contact, both through vaginal delivery or through people touching or kissing, Rhian told Yahoo7.

Her doctors had confirmed that Ernie had not contracted the virus through her.

"So that leaves it down to someone that has been in contact with my child that either kissed him or didn’t wash their hands, even though I had specifically asked for everyone to do so," she said.

She shared the post to raise awareness of the dangers - and to remind people that it is important to respect the wishes of parents.

"When being around a newborn, personal hygiene is everything, remember to keep your hands clean, don’t kiss and respect the wishes of parents."