According to a recent study from the Perelman School of Medicine at the University of Pennsylvania, adults with atopic dermatitis (AD) have a 34 percent higher risk of developing new-onset inflammatory bowel disease (IBD) compared to people who do not have the skin condition, and children have a 44 percent higher risk. Additionally, the likelihood of acquiring IBD increased with the severity of AD. These results dispel uncertainty from earlier research, particularly across populations of youngsters and between Crohn’s disease and ulcerative colitis, two kinds of inflammatory bowel illness. This study’s findings, which were just published in JAMA Dermatology, may help develop new IBD and AD treatments.
IBD includes ulcerative colitis and Crohn’s disease, both of which are conditions marked by persistent inflammation of the digestive tract. Although IBD affects the gut and AD affects the skin, both conditions are immune system-driven and are characterized by significant inflammation.
Senior author Joel M. Gelfand, MD, the James J. Leyden, M.D. Endowed Professor in Clinical Investigation in the department of Dermatology at Penn, said that in order to provide the best standard of care, clinicians must have a thorough understanding of atopic dermatitis and the course of their patients’ disease. “There are more and better treatments for AD being developed today, and this trend is likely to continue. But healthcare professionals need to be aware of how those therapies can affect other autoimmune illnesses.
Some currently available drugs can worsen the symptoms of another autoimmune illness in patients who also have AD or can help treat two immune diseases concurrently.
Although this is not the first study to examine AD and IBD, it advances other studies due to its scale, population of adults and children, and distinction between ulcerative colitis and Crohn’s disease. More than 1 million children and people with AD participated in the Penn study, with individuals ranging in age from one month to eighteen years.
If Crohn’s disease and ulcerative colitis were examined independently, AD was not associated with a higher incidence of ulcerative colitis in children unless the children had severe AD. However, children with AD had a relative risk of Crohn’s disease that was elevated by between 54 and 97 percent, and among those with severe AD, the risk was almost five times higher. Results for adults were simpler to understand. Adults with AD exhibited a 36% greater relative risk of Crohn’s disease and a 32% greater relative risk of ulcerative colitis. The absolute additional risk of acquiring IBD in people with atopic dermatitis is still fairly low, according to Gelfand, but the relationship is significant for better understanding health outcomes in AD.
Atopic dermatitis affects millions of people, thus this tiny increase in risk dispersed over so many people is probably significant from the standpoint of public health.
Despite not examining the underlying cause of IBD associated to AD, Penn researchers have compelling suggestions about the connections.
“AD and IBD can cause alterations in the microbiome, chronic inflammation, and dysfunction in the skin and gut barrier, respectively,” said Gelfand, who is also the head of the Center for Clinical Sciences in Dermatology at Penn. Additionally, several cytokines and proteins that are involved in immune system function and appear to be connected to AD and IBD exist.
For instance, we believe that the culprits may be dysfunctional T cell subsets that are linked to both AD and IBD. Further research is required to determine what is occurring at the microscopic level and whether proteins or structures might be used as therapeutic targets for either or both disorders.
Leading authority on psoriasis, a condition that has been genetically linked to inflammatory bowel disease (IBD), Gelfand is well aware of how closely skin health can influence other regions of the body. Additionally, he and his colleagues are researching how infections, neurologic and mental problems, and cardiovascular disease are related to AD.
According to Gelfand, “studying the link between skin diseases and other diseases not only offers new insight into how these diseases can affect a patient who has both of them, but these studies are particularly powerful because they additionally highlight the distinctive features of each disease and how they behave individually.”
Pfizer Inc. provided assistance for this study. Chiesa Fuxench, Wan, Syed, and Gelfand have all received unrelated grants, payments, or fees from Pfizer. The decision to submit the paper for publication, as well as the preparation, review, and approval of the manuscript, were not influenced by the study’s funding source. The decision was made by the authors.