Eczema and chronic skin diseases: this ingredient would increase the risk of dry skin and itching

A diet high in salt could increase the risk of eczema, a new study reveals. AsiaVision/etty Images

Family history and allergies can be risk factors for certain chronic skin diseases, including eczema. Which can be accentuated by pollution, perspiration, cold, hard water, certain cosmetics, and even certain foods. A new American study points to an ingredient omnipresent on our plates, responsible for an increased risk of dry skin and itching.

According to Inserm, "atopic dermatitis, also called atopic eczema, is a chronic inflammatory disease of the skin, ( …) characterized by dry skin associated with eczema-type lesions (redness and itching, blisters, oozing and crusts) which develop in outbreaks". The scientific research organization notably involving genetic and environmental factors, and evoking the impact of such an illness on mental health. Numerous studies around the world have reported for several years an increase in cases of chronic disease, particularly in industrialized countries, linked to environmental changes and our lifestyles.

An observation which led a team of American researchers, from the University of California at San Francisco (UCSF), to focus on the impact of ;#39;an everyday ingredient for skin dryness and itching, and more generally for eczema. To do this, they analyzed data from 215,832 adults aged 37 to 73 from the UK Biobank, a large long-term study carried out in the United Kingdom to assess the influence of genetic predisposition and ;#39;environmental exposure on the development of many diseases.

Urine samples and electronic medical records were analyzed for the purposes of this work. The objective being to determine the quantity of sodium, a component of salt, consumed by the participants, and to compare this data with a possible diagnosis of atopic dermatitis.

Published in the journal JAMA Dermatology, their research shows an increased risk of being diagnosed with eczema (+11%), cases of eczema (+ 16%) and chronic disease severity (+11%) for each additional gram of sodium passed in urine over a 24-hour period.

Half a teaspoon of salt

To validate these results, the researchers looked at data from another population, namely 13,014 American adults from the National Health and Nutrition Examination Survey. And the finding is the same: consuming an extra gram of sodium per day, or the equivalent of half a teaspoon of salt, increases the risk of suffering from an active case of eczema by 22%. The authors of the study actually advise affected patients to limit their salt intake to better manage eczema flare-ups.

"Most Americans eat too much salt and can safely reduce their intake to recommended levels", said Katrina Abuabara, associate professor of dermatology at UCSF, in a statement. And to conclude: “Eczema flare-ups can be difficult for patients to live with, especially when they cannot anticipate them and do not have recommendations on what they can do to avoid them.”

According to data made public by the National Eczema Association, more than 31.5 million people suffer from some form of eczema in the United States, or about 10% of the population. In France, more than 2 million people are affected by this chronic disease, including 100,000 who suffer from severe eczema, according to the French Eczema Association. Which indicates that the number of patients has tripled in 30 years.