A mother has warned of the dangers of babies getting cold sores after her daughter contracted the virus and nearly died.
In a Facebook status, Claire Henderson that the baby girl, Brooke, was hospitalised for five days after the sores started appearing on her face, in the back of her throat and on her lips.
She said a friend who knew about the potential dangers told her to take her to hospital immediately.
Ms Henderson, from Doncaster, said: "I know this sounds like I am scaremongering but if my friend had not told me about this my baby girl could have been very seriously ill.
"I noticed the signs early and got her to A&E, we have now been in hospital on a drip for three days and have got another two to go. She was VERY lucky, all her tests came back clear."
She explained that babies cannot fight off the cold sore virus, also known as herpes simplex, before they are three months old because their immune systems are not strong enough.
Brooke is now recovering well and all her tests for brain and liver damage have come back clear.
Ms Henderson said: "The moral of the story is DO NOT let anyone kiss your newborn’s mouth, even if they don’t look like they have a cold sore – 85 per cent of the population carry the virus.
"And if someone has a cold sore ask them to stay away until it has gone."
According to the World Health Organisation the oral version of the virus, HSV-1, is common throughout the world and is a lifelong infection with no cure though the symptoms can go into remission.
Neonatal herpes, which can also be transmitted by infected mothers during childbirth, is rare but can be fatal.
The WHO recommends that people infected with HSV-1 who aren’t showing symptoms should avoid kissing babies as the virus can be transmitted in the saliva.
In 2013, a baby died after contracting the virus from his father when he was just two weeks old.
Kaiden McCormick, from Bootle in Merseyside, died of multiple organ failure after his father Carl kissed him.