By Lisa Rapaport

Without good information on how well different nonprescription skin creams work for infant eczema, parents may want to try petroleum jelly first because it tends to be cheapest, a recent study suggests.

Up to one in five children develop eczema at some point, and half of them get this inflammatory skin condition as babies. The condition can lead to rashes, itchy skin and infections when kids scratch, and it's also linked to other health problems like asthma, allergies, sleep disorders, developmental delays and behavior issues.

Doctors often tell parents to cover babies head to toe in moisturizers to prevent flare-ups and soothe inflamed skin.

For the current study, researchers examined the cost per ounce of Vaseline petroleum jelly and other non-prescription options such as Aquaphor Baby Healing Ointment, Cetaphil Moisturizing Cream and Aveeno Eczema Therapy Moisturizing Cream. 

"Petroleum jelly is an extremely effective moisturizer," said lead study author Dr. Shuai Xu, a dermatology researcher at Northwestern University in Chicago. "It also happens to be one of the most affordable."

While adults may not want to coat their whole body with petroleum jelly because it's messy and greasy, babies won't care much about getting their clothes dirty, Xu added by email. This product also tends to be free of artificial fragrances or preservatives that can act as irritants or allergens in the future. 

To determine the typical cost of covering babies in moisturizers each day, researchers averaged the list price for seven of these products at four different retailers. Then, they calculated a price per ounce as well as the cost per typical application to fully moisturize an average size 6-month-old baby once every day for six months.

Vaseline was cheapest by both measures, at an average price of 13 cents an ounce and 4 cents per application, for a total cost over six months of $7.30, researchers report in JAMA Pediatrics. 

Aquaphor was the fourth most expensive option, at an average price of 94 cents an ounce and 31 cents per application, for a total cost over six months of $56.58.

Aveeno was second in expense only to Vaniply Ointment. Aveeno's eczema cream cost $1.40 per ounce and 45 cents per application, for a total of $82.13 over six months. 

The study didn't look at the effectiveness of different options, and researchers didn't test out how much moisturizer parents actually applied to determine typical costs. 

Instead, researchers assumed all the moisturizers were equally effective, which may not be true, said C. Michael White, chair of the University of Connecticut School of Pharmacy in Hartford.

"However, there is a very low risk of harm from using a moisturizer without artificial scents so it is something that parents can do as more data is generated," White, who wasn't involved in the study, said by email. 

"At this point, I would choose the least expensive product to start and if you don't like the feel of it (petroleum jelly can be very greasy and some people don't like the feel of it) or you believe something else might be easier to use you can try it and be able to compare the effects to the less expensive option," White added. 

Trying these moisturizers is a good option because left untreated, parents don't always realize that eczema can go beyond just itchy skin to encompass a wide variety of health problems, Xu said.