New thinking on the cause of eczema is prompting some scientists to investigate whether how parents care for their infants’ skin has contributed to the disease’s growth.
How often a baby gets a bath, what is in the baby wash and shampoo and whether the skin is properly moisturized after bathing are things that could help bring on eczema, recent studies suggest. Researchers say many babies may be getting too many baths, and two to three a week is enough. Eczema causes patches of dry, itchy, inflamed skin that usually starts in early childhood.
Scientists increasingly believe that environmental factors, such as bathing, pollutants and indoor heating, can disrupt the skin’s ability to keep moisture in and allergens and microbes out. A weakened skin barrier—the outermost layer—allows outside irritants to penetrate the skin and spark an immune-system response. Other research has found that genetic variations in some eczema patients also can compromise the skin barrier.
Eczema was long believed to begin as an allergic reaction, perhaps to something a child ate or encountered, that then led to skin inflammation. But experts say decades of viewing allergies as the primary culprit behind eczema yielded few preventive strategies.
“The more we understand about the causes of eczema, the more it seems how we take care of the skin of babies may be relevant,” says Eric Simpson, associate professor of dermatology at Oregon Health & Science University in Portland. “Are the things we’re doing that we think are good for our babies causing eczema?” he says.
Eczema, formally known as atopic dermatitis, usually appears on the face and scalp of babies and in the crooks of elbows and backs of knees in older children. Prescription ointments can reduce the itching and redness but there isn’t a cure.
The condition usually develops before the age of 18 months, when a baby’s skin is still developing. It can come and go for months or years and often disappears by adolescence. Occasionally it persists into adulthood. The American Academy of Dermatology estimates 10% to 20% of children get eczema, up from just 3% in 1960. It isn’t clear if the rate is still rising.
In a recent study, Dr. Simpson and a team of investigators from the U.K. looked at whether protecting the skin barrier of infants with a moisturizer could help prevent eczema. They divided 124 newborns at high risk for eczema because of family history into two groups. Parents of the first group were instructed to apply a fragrance-free moisturizer all over their babies’ body once a day. In the other group, parents were asked not to use moisturizer. When the babies were 6 months old, the incidence of eczema in the moisturized group was about half that of the controls, or 22% versus 43%.
“There hasn’t been much ever before that’s been shown to alter the chances of a child to develop eczema,” says Seth Orlow, chairman of the Ronald O. Perelman Department of Dermatology at NYU Langone Medical Center in New York. “This suggests we can do something low-tech and change whether a child gets this disease. Wow, that’s pretty exciting if so,” says Dr. Orlow, who wasn’t involved in the research on eczema and moisturizers.
Dr. Simpson says he is planning, with funding from the National Institutes of Health, a large, multicenter trial to test whether the early results hold up. He will include a few other skin-care practices he expects could help prevent eczema, including bathing the infant no more than two or three times a week and using only small amounts of mild, fragrance-free cleansers.
The American Academy of Pediatrics recommends on its website bathing an infant three times a week or less, and applying a fragrance-free, hypoallergenic moisturizing lotion immediately after the bath to help keep the skin from drying out.
Fragrances and some soap and shampoo ingredients, such as sodium lauryl sulfate, can irritate the skin, experts say. They recommend using moisturizers that are thick or oily, because these can do a better job at sealing moisture in.
“We’ve become more aware how important the skin barrier is,” says Megha Tollefson, one of the authors for the academy of a coming clinical report on eczema. “It’s definitely one of the most important areas we should be looking at for eczema,” says Dr. Tollefson, an assistant professor of dermatology and pediatrics at Mayo Clinic.
Many parents appear not to be following the academy’s recommendations. In a report published online in the journal Pediatric Dermatology
in September, Dr. Simpson analyzed the usage of baby-skin-care products in the U.S. based on data collected by market-research firm Mintel Group. Households reported using baby wash and shampoos around five times a week on average.
“People are bathing their babies too much,” Dr. Simpson says. “If you expose skin to water and let it air dry, that leads to dryness—like the bottom of a river bed that cracks open when it dries.”
Researchers in recent years have also found genetic links to eczema. One gene variation appears to reduce the amount of a protein called filaggrin, which helps the skin barrier hold in moisture. Studies have shown roughly half of people with moderate to severe eczema have filaggrin deficiency, while mild to moderate cases are much less likely to have the genetic problem.
Experts believe a breakdown of the skin barrier, either because of genetic or environmental factors, may explain in part the growth in the rate of eczema. Also important is the body’s immune response to allergens and other irritants. Some studies have shown that giving probiotics to women during pregnancy may reduce the risk of eczema, probably by changing the babies’ immune response.