The Link Between Skin Breakouts and Food Allergies

There is a mysterious connection between the skin and the gut, specifically with regard to food allergies. For reasons scientists don't yet fully understand, chronic skin conditions, such as eczema, are linked to food allergies.

While the prevalence of food allergies in children is only about 8%, this rate rises to 30% in children with eczema. Researchers have discovered that in some cases, eczema can precede a food allergy.

Skin Breakouts

According to Medical Express, a new study conducted by researchers at Yale University School of Medicine presents a new hypothesis about this connection: skin damage can trigger food allergies.

By examining mice in the lab with various types of skin injuries, including wounds and UV damage, the researchers found that introducing new food proteins directly into the intestines via a feeding tube at the time of skin damage triggered new food allergies in the animals.

The allergen—a substance that causes allergic reactions—had to be introduced within a few hours of the skin lesion. Foods introduced the next day appeared to be safe.

Before these findings, it was unclear whether events occurring in the body at this distance could be linked through the immune system to trigger an allergy, according to the researchers.

"It's a change in mindset, because these things don't have to happen in the same place in the body," said lead researcher Daniel Weissman.

He added, "We need to study how these different organ systems communicate with each other."

The Skin-Gut Connection

The existence of food allergies is somewhat of a scientific mystery because the gut tends to be immune-tolerant.

The immune environment in our digestive system evolved to allow us to safely consume a variety of foods and to allow both foreign and beneficial bacteria to settle in our gut.

If food allergies are actually caused by an immune reaction in a completely different organ, such as the skin, that might partly explain this dilemma.

Egg Allergy

The researchers tested several types of skin injuries, including puncture wounds and sunburn, while simultaneously feeding mice ovalbumin, an egg white protein that is a common food allergen, via a feeding tube.

The researchers found that these conditions, which combine skin damage with the introduction of a novel allergenic food, triggered an allergy to egg white protein. The same response did not occur in mice previously exposed to egg white protein.

The scientists identified several cytokines—molecules released by the immune system when it is activated—that were essential for the development of egg white allergy. They hypothesize that a type of immune cell is responsible for coordinating signals between the skin and the gut to trigger an allergy, and they are currently working to identify these intermediate cells.