Over the past decades, the incidence of chronic inflammatory disorders such as autoimmune and type 2 allergic diseases has increased worldwide. A growing body of evidence indicates that this rapid and relatively recent onset of allergic epidemics is the consequence of environmental and behavioral changes collectively known as the “westernized lifestyle”
More recently, it was hypothesized that such a lifestyle could cause epithelial barrier dysfunction, an event leading to enhanced ingress of allergens at mucosal surfaces, systemic allergen sensitization, and ultimately the development of allergic diseases.
Atopic dermatitis (AD) is a pruritic skin condition of unknown origin that usually starts in early infancy (an adult-onset variant is recognized); it is characterized by pruritus, eczematous lesions, xerosis (dry skin), and lichenification (thickening of the skin and an increase in skin markings).
The prevalence rate for atopic dermatitis (AD) is 10-12% in children and 0.9% in adults. More recent information examining physician visits for AD in the United States from 1997-2004 estimates a large increase in office visits for AD occurred.
What’s the treatment available?
Depending on the climate, patients usually benefit from 5-minute, lukewarm baths followed by the application of a moisturizer such as white petrolatum. Frequent baths with the addition of emulsifying oils (1 capful added to lukewarm bath water) for 5-10 minutes hydrate the skin. The oil keeps the water on the skin and prevents evaporation to the outside environment.
Topical steroids are currently the mainstay of treatment. In association with moisturization, responses have been excellent.
Some other medication such as Janus kinase (JAK) inhibitors, is used with severe forms of the disease.
Additionally, advise patients to apply a barrier of petroleum jelly around the mouth prior to eating to prevent irritation from tomatoes, oranges, and other irritating foods.
Avoid foods that provoke acute allergic reactions. Most frequently, allergic reactions occur to peanuts (peanut butter), eggs, seafood, milk, soy, and chocolate.
What’s new on the prevention of this skin allergy?
Professor Ben Marsland from the Central Clinical School’s Department of Immunology, together with Swiss colleagues at the University Hospital of Lausanne (CHUV), showed that the fermentation of fiber in the gut by bacteria and subsequent production of short-chain fatty acids (SCFAs), in particular butyrate, protected against atopic dermatitis in mice.
The researchers fed mice a diet high in fermentable fibre or gave them purified SCFAs. They labeled the butyrate with isotopes and tracked it in the body, it took only minutes to reach the skin where it enhanced the metabolism of keratinocytes, priming them to mature and produce the key structural components required for a healthy skin barrier.
Actively improving the skin barrier could have protective effects against environmental exposures that cause allergies and perhaps even other skin diseases which are underpinned by a damaged or weak skin barrier.
One possibility to explore is whether this could help children who are at risk of developing skin allergies that cascade towards food allergies and asthma, the so-called ‘Atopic March’.
These findings show us that a high fiber diet may help to reduce the skin allergic events by improving the skin barrier. This may pave future criteria to modified the diet in children who have skin problems such as Atopic Dermatitis.
Aurélien Trompette, Julie Pernot, Olaf Perdijk, Rayed Ali A. Alqahtani, Jaime Santo Domingo, Dolores Camacho-Muñoz, Nicholas C. Wong, Alexandra C. Kendall, Andreas Wiederkehr, Laurent P. Nicod, Anna Nicolaou, Christophe von Garnier, Niki D. J. Ubags, Benjamin J. Marsland, (Juve 7, 2022). Gut-derived short-chain fatty acids modulate skin barrier integrity by promoting keratinocyte metabolism and differentiation. Mucosal Immunology. Retrieved from : https://www.nature.com/articles/s41385-022-00524-9
Photo by Iñigo de la Maza on Unsplash.