High-salt diet may increase eczema in adults, study finds

“We really wanted to understand the triggers of atopic dermatitis,” Katrina AbuaballahThe study's lead author, an associate professor of dermatology at the University of California, San Francisco School of Medicine, said that by some estimates, the prevalence of eczema has increased over the past century in ways that “cannot be explained by genetics alone.”

• The researchers found that each 1-gram increase in estimated daily salt intake was associated with an 11 percent increased risk of eczema in adults.
• The findings are based on urine samples and medical records from 215,832 adults from the UK Biobank. Five percent of participants – 10,839 – had been diagnosed with eczema and prescribed medication to treat the rash.
• The higher the amount of sodium detected in the urine sample, the more likely it was that the eczema would be more severe.

What we know about eczema and salt

Abuaballah said the UCSF findings were only a “small increase in risk” and that more research is needed. But he said there are several reasons why salt intake may be linked to eczema. The researchers found that sodium accumulates in the skin. Sodium can cause inflammation in the body, and epidemiological data suggests a person's diet is linked to eczema.

a study A study of children around the world published in 2013 found that regularly eating fast food, which is often high in salt, was linked to higher rates of eczema, but “there are lots of other factors at play that could explain the association” with fast food, Abu-Aballah said.

“I don't think that all eczema is related to salt,” Abuaballah says. “I think this is probably one of those things that's a trigger for some people.”

Abuaballah plans to conduct experiments to see whether reducing sodium intake can reduce the severity of eczema.

“We don't yet know if reducing sodium intake reduces the severity of eczema,” she says, “so we're doing more research before we can specifically recommend that or make any particular dietary recommendations.”

The findings do not show that salt causes eczema, but rather that there is a link between salt and eczema. Most study participants were white (95%), and UK Biobank volunteers tend to be older and healthier than the general population.

of National Eczema Association The National Institute on Aging also funded the study. Abuaballah has also received research funding and/or consulting fees from Pfizer, La Roche-Posay, Target RWE, Sanofi, Nektar, and Amgen.

Saranya WildsDermatologist Jonathan Myers, director of the Skin Regenerative Medicine and Skin Longevity Laboratory at the Mayo Clinic in Rochester, Minnesota, said the findings are “a great start to hypothesis-generating,” but that the data is based on subjects' one-time urine samples and the results are not conclusive.

“This is testing a potential hypothesis, but I don't think it's conclusive,” Wiles said. “We need to be careful how we interpret it.”

Bruce BrodClinical Professor of Dermatology, Perelman School of Medicine, University of Pennsylvania Although atopic dermatitis is most common in children, participants in this study were adults with an average age of 56.

“It's difficult to change treatment paradigms based on this study,” Brod said, “but I think it's a great example of bioepidemiology research that could potentially help inform further research.”

Eczema, or atopic dermatitis, is caused by a dysfunction of the skin barrier, Brod says, and the frequency of bathing, the temperature and humidity where you live, and what you're exposed to at home and work all play a role.

“We all love long, hot showers,” he says, “and while they can be relaxing, the heat, hot water, and soap can aggravate eczema.”

Tobacco smoke, other air pollutants, and certain fragrances in skin care products and soaps can also Atopic dermatitisAccording to the NIH.

Eczema is most likely to appear in areas where the skin folds, like the insides of the arms or behind the knees, and it can create a “vicious itch-scratch cycle,” where scratching the rash makes the inflammation worse and further weakens the skin barrier, Wiles said.

Wiles says people should moisturize their skin regularly to protect the skin barrier, and if the rash is “actively inflamed,” talk to a dermatologist about topical steroids and other treatments, as well as oral and injectable medications for more severe cases.

“The most important thing is barrier protection – keeping the skin barrier hydrated,” Wiles says. “You can also use over-the-counter moisturizers for eczema.”