Adults and children with atopic dermatitis at higher risk of IBD, new study finds

ISLAMABAD, Sep 08 (Online): About 223 million people around the world have atopic dermatitis — a chronic skin condition causing dryness, itching, and rash.

Of that number, about 43 million are children ages 1 to 4.
Atopic dermatitis is the most common type of eczema and because it is associated with inflammation, previous research shows people with this skin disease are at a higher risk for heart diseasesTrusted Source, asthmaTrusted Source, chronic kidney diseaseTrusted Source, and autoimmune diseasesTrusted Source such as rheumatoid arthritis, celiac disease, and the two types of inflammatory bowel disease (IBD) — Crohn’s disease and ulcerative colitis.

Now, researchers from the University of Pennsylvania are providing more insight into how atopic dermatitis increases a person’s risk for IBD.
The scientists say they found that both children and adults with atopic dermatitis have an increased risk for IBD, however, the risk varies depending on age, atopic dermatitis severity, and type of IBD.

What is IBD?
Inflammatory bowel disease (IBD) is a term for two conditions (ulcerative colitis and Crohn’s disease) that are characterized by chronic inflammation of the digestive tractTrusted Source.

It is an autoimmune disease, meaning the body’s immune system mistakes healthy tissues in the digestive tract as something foreign, causing it to attack.

Researchers still do not know exactly what causes IBD. However, there are certain known risk factors for IBD including ageTrusted Source, ethnicityTrusted Source, geneticsTrusted Source, and environmental factorsTrusted Source.

Some symptoms of inflammatory bowel disease
Unexplained weight loss
Chronic diarrhea
Stomach pain or cramps
Kidney stones
Eye inflammation
Joint pain
There is currently no cure for IBD.

However, the condition can be managed with a combination of lifestyle changesTrusted Source — including dietTrusted Source and managing stressTrusted Source — in addition to medicationsTrusted Source. Occasionally surgeryTrusted Source to help alleviate symptoms.

IBD and atopic dermatitis
According to Dr. Joel Gelfand, a professor in clinical investigation and the director of the Center for Clinical Sciences in Dermatology at the Perelman School of Medicine at the University of Pennsylvania and a senior author of this study, said his team decided to study the potential link between IBD and atopic dermatitis in both children and adults as another chronic skin condition called psoriasis has long been known to be associatedTrusted Source with IBD and has some shared genetics.

“Less work has been done with atopic dermatitis, which is a very common skin disorder, and IBD,” he told Medical News Today. “Both atopic dermatitis and IBD are diseases with barrier dysfunctionTrusted Source, microbiomeTrusted Source alterations, and chronic inflammation suggesting commonalities between the two diseases.”

This is not the first study to look at a link between atopic dermatitis and IBD. A studyTrusted Source of a Korean population published in 2020 found people with any atopic disease — including atopic dermatitis — were at an increased risk for developing IBD. The risk increased depending on how many atopic diseases a person had.

A studyTrusted Source in 2022 found a causal linkTrusted Source between atopic dermatitis and IBD, but not IBD and atopic dermatitis.
Conversely, a studyTrusted Source published in 2021 reported atopic dermatitis was not independently associated with IBD development.
Statistically significant increase

For this study, Gelfand and his team compared data from more than 409,000 children and 625,000 adults with atopic dermatitis and compared them to more than 1.8 million children and almost 2.7 million adults without the disease.

Upon analysis, the scientists reported a “statistically significant” increased risk of incident or new-onset IBD among 44% of children and 34% of adults with atopic dermatitis, compared to the control groups.
Additionally, researchers reported that the IBD risk increased with worsening atopic dermatitis severity.

“The results are important… the association is stronger with increasing severity of atopic dermatitis,” Gelfand said. “I was a bit surprised that in children the association was stronger for Crohn’s disease than ulcerative colitis.”

“Both ulcerative colitis and atopic dermatitis are thought to be Th2 diseasesTrusted Source, so we hypothesized a stronger relationship between atopic dermatitis and ulcerative colitis compared to atopic dermatitis and Crohn’s disease,” he added. “This finding is a reminder of the importance of epidemiological studies, which is the science of understanding the distribution and determinants of health in humans. It is not uncommon for biologically derived hypotheses to be reversed when studied in patients.”
“The association in adults with more severe atopic dermatitis approaches the strength of association we see with psoriasis and IBD, which I think is a striking finding that needs more exploration,” Gelfand noted.