The $4.45 product experts believe may prevent newborns developing eczema.

My son had to struggle with red itchy skin as a newborn.

When he was four months old, his eczema got so bad he had weeping blisters on his chest.

He was also covered in red hives when I took him to a private London dermatologist, and for around $400, we finally had a plan that seemed to work.

Now new research suggests I could have spent $4.45 at my local supermarket to help prevent my son from developing eczema in the first place.

I’m kicking myself now because my grandmother told me about Vaseline.

US researchers found that moisturising newborns with petrolatum-based emollients until they were six months old had a 50 per cent chance of preventing eczema (also known as atopic dermatitis).

Parents in the study gave high-risk eczema newborns a full-body rub at least once a day within three weeks of birth for six months.

They found the treatment to be a "feasible, safe, and effective approach for atopic dermatitis prevention".

Even the cheapest product they trialled - petroleum jelly - helped prevent a very expensive problem.

'One in five' babies

In Australia, around one in five children develop eczema before the age of two, according to the Australian Society of Clinical Immunology and Allergy (ASCIA).

"Eczema has a huge toll on families," paediatric dermatologist Dr John Su told the ABC.

"Babies don't sleep, they get infected, they're constantly scratching, they get restless. The parents don't sleep, they get sleep deprived and they can't go to work.

"I've seen parents split up over kids with eczema."

'Minimal risk'

One of the study's authors, Dr Steve Xu said eczema was "terrible" for kids and their family.

“Eczema can be devastating," Dr Xu told Northwestern Now.

"Beyond the intractable itch, a higher risk of infections and sleep problems, a child with eczema means missed time from school, missed time from work for parents and huge out-of-pocket expenses. So if we can prevent that with a cheap moisturiser, we should be doing it,” he added.

The physician in dermatology at Northwestern University Feinberg School of Medicine said there was minimal risk involved in over-the-counter products, such as petroleum jelly, Aquaphor, Cetaphil and Aveeno.

“We’re putting Vaseline on these babies to potentially prevent a very devastating disease,” he said.

At this stage, the research suggests that this is an effective treatment only for newborns already at high-risk of developing eczema.

For more information see your local doctor.