Risk of Inflammatory Bowel Disease in Patients with Atopic Dermatitis

Importance  

Data on the association between atopic dermatitis (AD) and inflammatory bowel disease (IBD) are inconsistent. Few studies have examined the association of AD or AD severity with the risk of ulcerative colitis (UC) and Crohn’s disease (CD) separately.

Goals  

To examine the risk of new-onset IBD, UC, and CD in children and adults with AD.

Design, environment and participants  

This population-based cohort study evaluated AD patients matched to up to 5 controls on age, practice, and index date. Treatment exposure was used as an indicator of AD severity.

Data were retrieved from The Health Improvement Network , a UK electronic medical record database, from January 1, 1994 to February 28, 2015. Data analysis was conducted from January 8, 2020 to January 30. June 2023.

Main results and measures  

Outcomes of interest were incident IBD, UC, and CD. Logistic regression was used to examine the risk of each outcome in children and adults with AD compared to controls.

Results 

A total of 1,809,029 pediatric controls were matched with 409,431 children with atopic dermatitis (AD) (93.2% mild, 5.5% moderate, and 1.3% severe). The pediatric cohort had a median age of 4 to 5 years (overall range, 1 to 10 years) and was predominantly male (936,750 [51.8%] controls, 196,996 [51.6%] with mild AD, 11 379 [50.7%] with moderate AD and 2,985 [56.1%] with severe AD), and with similar socioeconomic status.

A total of 2,678,888 adult controls were matched with 625,083 adults with atopic dermatitis (AD) (65.7% mild, 31.4% moderate, and 2.9% severe). The adult cohort had a median age of 45 to 50 years (overall range, 30-68 years) and was predominantly female (1,445,589 [54.0%] controls, 256,071 [62.3%] with mild AD, 109,404 [55.8%] with moderate AD and 10,736 [59.3%] with severe AD).

In fully adjusted models, children with AD had a 44% increased risk of IBD (HR, 1.44; 95% CI, 1.31-1.58) and a 74% increased risk of CHD (HR, 1.74; 95% CI, 1.54-1.97), which increased with worsening of AD; however, they did not have an increased risk of UC (HR, 1.09; 95% CI, 0.94-1.27) except those with severe AD (HR, 1.65; 95% CI, 1.02 -2.67).

Adults with AD had a 34% (HR, 1.34; 95% CI, 1.27-1.40) increase in IBD, a 36% (HR, 1.36; 95% CI, 1 . 26-1.47) risk of BC and a 32% (HR, 1.32; 95% CI, 1.24-1.41) increased risk of UC, and the risk increased with worsening of AD .

Conclusion and relevance  

In this cohort study, children and adults with atopic dermatitis (AD) had an increased risk of IBD, and the risk varied by age, AD severity, and IBD subtype. These findings provide new insights into the association between AD and IBD.

Clinicians should be aware of these risks, particularly when selecting systemic treatments for AD in patients who may have overlapping gastrointestinal symptoms.

Comments

Adults with atopic dermatitis (AD) have a 34 percent higher risk of developing new-onset inflammatory bowel disease (IBD) compared to people without this skin condition, and children have a 44 percent higher risk , according to a new study from the Perelman School of Medicine at the University of Pennsylvania.

As the severity of AD increased, the risk of developing IBD increased.

These findings clarify the ambiguity of previous research, especially among populations of children and between different types of inflammatory bowel disease: ulcerative colitis and Crohn’s disease. The insights offered by this study, recently published in JAMA Dermatology , could lead to new treatments for both IBD and AD.

IBD encompasses the diseases ulcerative colitis and Crohn’s disease, which are disorders involving chronic inflammation of the digestive tract. While IBD is located in the gut and AD affects the skin, both diseases are driven by the immune system and are classified by severe inflammation.

"It is imperative that clinicians understand atopic dermatitis and our patients’ journey with it in order to provide the best standard of care," said senior author Joel M Gelfand, MD, James J. Leyden, MD Clinical Research Professor. in the Penn Department of Dermatology. "There are new and better treatments for AD today, and there will likely continue to be more. But providers need to understand how those treatments might affect other autoimmune diseases. For patients with AD and another autoimmune disease, some currently available medications can exacerbate the symptoms of your other illness or can help treat two immune diseases at the same time.

While this is not the first study to explore AD and IBD, its size, its population composed of adults and children, and its separation between ulcerative colitis and Crohn’s disease are advances on previous research. The Penn study included more than 1 million children (participants from ages 1 to 18) and adults with AD.

When looking at ulcerative colitis and Crohn’s disease separately, AD was not associated with greater ulcerative colitis in children, unless the children had severe AD. However, children with AD had a 54 to 97 percent higher relative risk of Crohn’s disease, and among children with severe AD, their risk was approximately five times higher.

The results among adults were simpler. Adults with AD had a 32 percent higher relative risk of ulcerative colitis and a 36 percent higher relative risk of Crohn’s disease. Gelfand notes that the absolute additional risk of developing IBD in people with atopic dermatitis remains quite small, but the association is significant for better understanding health outcomes in AD. Furthermore, since millions of people suffer from atopic dermatitis.

Although the Penn researchers did not look at the root cause of AD-related IBD, they have strong hypotheses about the links.

"AD and IBD can cause microbiome changes , chronic inflammation, and skin and gut barrier dysfunction , respectively," said Gelfand, who is also director of Penn’s Center for Clinical Sciences in Dermatology. "There are also specific cytokines, certain types of proteins, that play a role in the activity of the immune system and that appear to be related to AD and IBD. For example, we believe that dysfunction of the types of T cells common to both EA and IBD could be to blame. "These need to be explored further to find out what is happening at a microscopic level and what proteins or structures could be used to treat one or both conditions."

As a leading expert on psoriasis, a disease known to be genetically linked to IBD, Gelfand is well aware of the extent to which skin health can affect other parts of the body. He and his colleagues are also studying AD’s relationship with infections, neurological and psychiatric disorders, and cardiovascular disease.

"Investigating the relationship between skin diseases and other diseases not only offers new insights into how these diseases can affect a patient with both, but these studies are especially powerful because they also highlight the unique characteristics of each disease and how they behave." individually". Gelfand shared.

Other Penn authors include Zelma C. Chiesa Fuxench, Joy Wan, Sonia Wang, Maha N. Syed, and Daniel Shin. This study was supported by Pfizer Inc. Chiesa Fuxench, Wan, Syed and Gelfand received grants, compensation or honoraria from Pfizer not related to this study. The funder of the study was not involved in the collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; or decision to submit the manuscript for publication. The authors had final approval on the manuscript.