Pediatric researchers at Oregon Health & Science University have found that applying a plain emollient – including petroleum jelly – to an infant’s entire body once daily, starting before nine weeks of age, reduced the cumulative incidence of atopic dermatitis (eczema) by 16% by age 24 months. The findings, published in July 2025 in JAMA Dermatology, come from the CASCADE trial (Community-based Assessment of Skin Care, Eczema, and Allergies), the largest community-based randomized clinical trial to date testing this approach in infants not specifically screened for eczema risk. Lead researcher Dr. Eric L. Simpson and colleagues enrolled 1,247 infant-parent pairs from 25 pediatric and family medicine clinics across four US states.
Petroleum jelly – also called petrolatum or white petrolatum – is a semi-solid mixture of hydrocarbons derived from petroleum. In its purified form, it acts as an occlusive agent: it sits on top of the skin and locks moisture in by forming a protective seal. It contains no fragrances, preservatives, or common allergens. Atopic dermatitis (often called eczema) is a chronic inflammatory skin condition that causes dry, itchy, and sometimes cracked skin. It affects up to 25% of children, and an estimated 60% of people with eczema develop it during their first year of life.
Understanding what drives eczema in infancy helps explain why petroleum jelly has attracted so much research attention. The condition is not just a surface problem – it involves a failure of the skin barrier from the ground up.
Why Eczema Starts So Early in Life
Many babies with eczema are born without enough of a special protein called filaggrin, which is responsible for forming a protective barrier between the baby’s skin and their environment. Without enough filaggrin, the top layer of the skin won’t work properly, and the baby will have trouble keeping moisture in. When that barrier breaks down, environmental irritants, allergens, and bacteria gain entry more easily, triggering inflammation. That inflammation is eczema.
The gene responsible for filaggrin production is faulty in more than 50% of people with atopic dermatitis. But genetics is only part of the picture. Babies who have a biological family history of seasonal allergies, asthma, or atopic dermatitis are more likely to develop the condition. Environmental exposures in the first weeks of life – from certain soaps to indoor allergens – can accelerate its onset. This interplay between a compromised skin barrier and the outside world creates a window of vulnerability that researchers have been trying to close for over a decade.
Skin barrier dysfunction early in life serves as a central event in the pathogenesis of atopic dermatitis. That single observation has fueled years of research into whether supporting the barrier with a simple moisturizer from birth could interrupt the process before it begins.
What the CASCADE Trial Found
To address existing gaps in the evidence, the CASCADE trial was a pragmatic, randomized, single-blind clinical trial involving 1,247 infant-parent pairs who were not selected for atopic dermatitis risk, drawn from 25 pediatric and family medicine clinics in four states, enrolling from July 2018 to February 2021. This matters because most earlier studies focused only on infants already considered high-risk – meaning they had a parent or sibling with eczema, asthma, or hay fever. CASCADE was different: it enrolled babies from the general population, making its results far more broadly applicable.
Applying a daily emollient on infants younger than nine weeks reduced the risk for atopic dermatitis by 16% at 24 months compared with usual care, researchers reported in JAMA Dermatology. Participants assigned to the daily moisturizer group were instructed to use the supplied emollient applied to the entire body once daily, with the scalp and diaper area excluded if preferred by the family. The emollients used in the trial were selected for their ability to improve skin barrier function and their lack of common irritants and allergens – a profile that petroleum jelly fits well.
The randomized clinical trial found that daily emollient application beginning before age nine weeks in a representative US population not selected for risk reduced the cumulative incidence of atopic dermatitis at age 24 months, and implementing this approach to pediatric skin care may be a feasible way to reduce the burden of atopic dermatitis in US communities. An accompanying editorial published alongside the CASCADE results noted that the benefit appeared particularly promising for children in lower-risk families – a group that might not otherwise be told to take any preventive steps at all.
A Decade of Evidence Building
The CASCADE trial did not emerge from nowhere. Research connecting early moisturizer use with eczema risk reduction has been accumulating since at least 2014. Dr. Xu and his team at Northwestern built on a 2014 study of 124 babies, in which researchers from Oregon Health & Science University found that parents cut their newborns’ risk of atopic dermatitis in half when they moisturized them daily, or at least 5 times a week, everywhere but the scalp, for their first six months of life.
That 2014 finding was later analyzed for cost-effectiveness in a study led by Dr. Steve Xu, a resident physician in dermatology at Northwestern University Feinberg School of Medicine, and published in JAMA Pediatrics. By using the cheapest moisturizer in the study – petroleum jelly – the cost benefit for preventive moisturization was only $353 per quality-adjusted life year. Quality-adjusted life year, or QALY, is a standard measure used to assess how cost-effective a medical intervention is. A figure this low signals exceptional value. A six-month supply of petroleum jelly was just $7.30, the cheapest of all the moisturizers in the analysis.
However, the picture became more complicated as larger trials followed. A 2020 multicenter randomized controlled trial by Chalmers and colleagues included 1,394 infants who received a daily application of petroleum-based emollient beginning within the first three weeks of life until the child was one year of age. There were no significant differences in the incidence of atopic dermatitis at two years of age between the groups. A separate large Scandinavian trial the same year found similar null results. These conflicting findings meant that, for several years, the science remained genuinely unsettled.
The CASCADE trial has now shifted the weight of evidence. Its broader population base, real-world clinic setting, and inclusion of low-risk families add a layer of external validity that earlier trials often lacked.
Does Petroleum Jelly Prevent Eczema in Babies?
This is the question most parents search for. The short answer, based on current evidence, is: it may reduce risk, but it is not a guarantee.
Despite early enthusiasm, routine emollient application from birth has not been universally shown to prevent eczema development in high-risk infants across all studies. The CASCADE trial showed a meaningful 16% reduction in the general infant population, which is clinically significant at a population level. For individual families – especially those without a strong family history of eczema – the absolute risk reduction is modest but real, and the intervention itself carries virtually no downside.
It is also worth noting what petroleum jelly does extremely well even outside of prevention. Petroleum jelly is one of the most cost-effective approaches to treat eczema flare-ups, helping address dryness by protecting the skin barrier and moisturizing the skin. Petrolatum is one of the safest ingredients for infant skin. It contains no fragrances, preservatives, or potential allergens. For parents managing active eczema, it is also well-regarded by dermatologists. A good moisturizer, fragrance-free cream, or ointment such as petroleum jelly, used several times daily, will help a baby’s skin retain its natural moisture.
So even if its preventive role is not absolute, its role in managing eczema once it appears is well-supported by clinical guidance from the American Academy of Dermatology.
Is Petroleum Jelly Safe to Use on Newborns?
Yes, when used correctly. Clinical trials have used petroleum jelly specifically in newborns for eczema prevention research. Emollients may be applied after bathing when the infant’s skin is still moist. White petroleum jelly is an inexpensive emollient that does not contain contact allergens and is ideal for routine use on infants’ skin.
One important caution: a 2016 study concluded that petroleum jelly rarely causes reactions and noted that there are no reported cases of contact anaphylaxis. Allergic reactions to plain petrolatum are extremely rare. However, parents should always choose 100% white petrolatum – not scented or colored variants, which may contain additives that irritate delicate newborn skin. Before applying petroleum jelly to a newborn as a preventive measure, speaking with your pediatrician first is advisable.
There are also a few situations where petroleum jelly should be avoided. It should not be applied over an active skin infection, as it may trap bacteria. Applying petroleum jelly over an active bacterial infection can trap bacteria and worsen the infection. It should also not be placed inside the nostrils in large amounts, and should never be used on burns. These are edge cases for most parents of healthy newborns, but worth knowing.
How to Use Petroleum Jelly on Infant Skin
The research offers clear guidance on method. According to the American Academy of Dermatology, people should apply petroleum jelly when the skin is damp for the best results. In practice, this means applying it within a few minutes of a bath – not after the skin has dried completely. This timing helps lock existing moisture into the skin rather than simply sealing a dry surface.
For parents following the CASCADE approach, the protocol was straightforward: apply the emollient to the entire body, except the scalp and diaper area if desired, once daily, and bathe children twice weekly with a gentle cleanser. Once daily, full-body, starting before nine weeks of age. There is no requirement to use a large amount – a thin, even layer is sufficient. The American Academy of Dermatology guidelines for treating baby eczema recommend moisturizing at least twice daily when managing active eczema, but once daily appears adequate for a preventive routine in a baby without symptoms.
For parents asking how often to apply petroleum jelly to an infant more generally – particularly if eczema is already present – twice daily is a reasonable starting point, and more frequently during flare-ups. Once a day or only after bathing is not sufficient for effective management of eczema-prone skin; moisturizing the child’s body at least twice a day is recommended. At each application, clean your hands first, use a clean applicator or freshly washed fingers, and pay attention to dry-prone areas like the cheeks, elbows, and knees.
Regarding what to look for when buying petroleum jelly for a baby: plain, unscented, 100% white petrolatum is the ingredient to seek. Brand-name Vaseline and generic white petrolatum are chemically identical when both are 100% petrolatum. There is no clinical evidence that more expensive ointments outperform basic petroleum jelly for this purpose.
The Bigger Picture: Eczema’s Burden on Families
The urgency behind this research becomes clearer when you consider what families face once eczema takes hold. The annual adjusted cost associated with atopic dermatitis management was conservatively estimated to be $5.3 billion USD in 2015 – a figure that has likely grown since. For individual families, the financial drain is direct and personal. Families caring for a child with eczema spend an average of $274 per month on medical costs.
The costs go well beyond money. Eczema can be devastating. 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. Children with eczema also face a higher risk of developing what researchers call the “atopic march” – a progression in which early eczema is followed by food allergies, hay fever, and asthma as the child grows. There is a growing body of data suggesting that atopic dermatitis makes individuals more susceptible to these comorbidities.
This is why a $7 jar of petroleum jelly draws attention from dermatology researchers. If a cheap, safe, widely available substance can meaningfully reduce the chance that a baby develops a condition with such far-reaching consequences, the cost-benefit calculation is hard to argue against. When parents or expectant parents ask if there’s anything they can do to reduce their baby’s risk of developing eczema, daily application of a bland moisturizer is a safe, straightforward approach, and the emollients studied can deliver potential health benefits whether children are at high or low risk.
You can also find related guidance on skin health at The Hearty Soul – including our article on natural ways to improve dry, flaky skin for adults managing similar moisture-barrier challenges.
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What the Evidence Does Not Yet Prove
Honest reporting requires acknowledging what remains unresolved. The CASCADE findings contradict prior studies that found no impact of various emollient regimens in infants without eczema. Researchers and clinicians will need to reconcile these differing results over time.
Two large randomized controlled trials with a combined sample of 3,791 infants found no evidence that early, regular use of emollients prevents atopic dermatitis among high-risk infants. This is a significant finding and should not be brushed aside. It suggests the benefit may be more pronounced in lower-risk or general populations than in families already dealing with a significant atopic history, though researchers are still working through why this might be.
There are also practical questions that remain open. The mean enrollment age of 24 days in the CASCADE study was older than in most other studies, and there is evidence that neonatal skin has increased permeability during the first few weeks of life, meaning pre-enrollment use of moisturizers by many participants may have conferred some baseline protection that requires further study. In other words, the timing of when you start may matter as much as what you use.
Read More: Scalp Eczema: 8 Natural Remedies for Red, Flaky, or Itchy Scalps
What This Means for Your Family
The evidence points in a direction parents can act on. For families with no notable history of eczema, asthma, or hay fever, the CASCADE trial suggests that starting a once-daily, full-body application of a plain, fragrance-free emollient – plain petroleum jelly qualifies – before your baby is nine weeks old may lower their risk of developing eczema by around 16% by their second birthday. That is a modest but meaningful reduction achievable with a product that costs under $10 and carries essentially no risk when used as directed.
For families with a first-degree relative who has eczema or other atopic conditions, the evidence is more mixed. Some earlier trials showed a 50% risk reduction in high-risk infants with daily moisturizing; others showed no significant benefit. The most cautious and practical advice remains the same across both groups: talk to your pediatrician before establishing a newborn skin care routine, choose a plain and fragrance-free moisturizer, apply it to damp skin once or twice daily, and stay consistent. If eczema develops despite your best efforts, the American Academy of Dermatology’s eczema treatment guidelines for babies outline a clear path forward, from moisturizing routines to topical medications when needed. No single intervention eliminates risk entirely, but the combination of a simple daily habit and early attention to your baby’s skin is about as low-cost and low-risk a preventive step as modern pediatric research has to offer.
Medical Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis, or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice because of something you have read here.
A.I. Disclaimer: This article was created with AI assistance and edited by a human for accuracy and clarity.
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