Excessive sodium intake can increase the risk of eczema flare-ups

UCSF study finds that changes in daily salt intake may explain eczema flare-ups.

A high-sodium diet may increase the risk of eczema, according to researchers at UC San Francisco (UCSF), who found that eating just one extra gram of sodium a day — the amount in a Big Mac — increases the likelihood of flare-ups by 22%. .

Eczema, also known as atopic dermatitis, is a chronic disease that causes dry, itchy skin. It is one of the most common skin conditions, affecting more than 31 million people in the US and one in 10 people will develop it at some point.

It has become increasingly common in recent years, especially in industrialized countries, involving environmental and dietary factors.

Sodium, which most people consume in the form of salt, increases the risk of high blood pressure and heart disease. And scientists recently discovered that sodium is stored in the skin, where it may play a role in inflammation in eczema.

Limiting dietary sodium could be an easy way for eczema patients to manage their disease.

““Most Americans eat too much salt and can safely reduce their intake to recommended levels.” said Katrina Abuabara, MD, associate professor of dermatology at UCSF and corresponding author of the study, which appears June 5, 2024, in JAMA Dermatology.

“Eczema flare-ups can be difficult for patients to deal with,” said Abuabara, who is also an associate professor of epidemiology at the UC Berkeley School of Public Health, “especially when they can’t predict them and they don’t have recommendations for what they can do to avoid them.”

For their cross-sectional study, the researchers analyzed data from more than 215,000 people aged between 30 and 70 from the UK Biobank, which includes urine samples and electronic medical records.

They could tell how much sodium each person was eating from urine samples. and they could see whether people had a diagnosis of atopic dermatitis, as well as the severity, from the prescription codes.

They found that every extra gram of sodium excreted in the urine over 24 hours was associated with an 11% higher chance of being diagnosed with eczema. 16% higher chance of having an active case. and 11% higher odds of increased severity.

They then looked at 13,000 US adults in the National Health and Nutrition Examination Survey and found that eating just one extra gram of sodium a day — about half a teaspoon of table salt — was associated with a 22 percent higher chance of having an active case of eczema.