A new study in Denmark shows that many people with newly diagnosed inflammatory bowel disease (IBD) also have hidradenitis suppurativa (HS), a chronic skin disease. A researcher says that rapid screening to determine whether people with inflammatory bowel disease have HS would be a sensible start.
A new study indicates that screening people with IBD to determine whether they have HS might be a good idea, since many people with IBD such as ulcerative colitis or Crohn’s disease have HS.
The discovery is intriguing, not least because there is a significant diagnostic delay in reaching a diagnosis of HS. Rapid screening for HS among people newly diagnosed with IBD might therefore make sense.
“Screening may help to reduce the diagnostic delay for people with HS. In addition, gastroenterologists just need to ask three quick questions and then refer to a dermatologist if HS is suspected,” explains a researcher behind the study, Johan Burisch, Professor and Chief Physician, Gastro Unit, Amager and Hvidovre Hospital, Hvidovre, Denmark.
The research has been published in the Journal of Crohn’s & Colitis.
Linking IBD and other inflammatory diseases
The study is part of a larger research project by Johan Burisch and colleagues. One aim is to determine the prevalence of other diseases among people with IBD.
In other studies, the researchers investigated the connection between IBD and osteoporosis or rheumatoid arthritis.
This study focused on HS, a chronic inflammatory skin disease with skin abscesses around the armpits, groin, buttocks and breasts.
“In this study, we joined forces with dermatologists at Bispebjerg and Frederiksberg Hospital since we know that people with IBD have an increased prevalence of HS, but whether this also applies at the time of diagnosis has been unclear,” says Johan Burisch, who emphasises that both genetic and environmental overlap between diseases with systemic inflammation is well known.
Many genetic risk factors for IBD and HD overlap, and smoking is a well-known risk factor for both diseases.
“This is basic physiology and environment, but we have lacked knowledge about what this means for the overlap between the two diseases, and how this affects patient outcomes when patients present with both,” adds Johan Burisch.
527 people diagnosed with IBD
The researchers examined data on 527 people newly diagnosed with IBD in the Capital Region of Denmark between May 2021 and April 2023 – of whom 38% were diagnosed with Crohn’s disease and 58% with ulcerative colitis.
Ulcerative colitis is a chronic intestinal disorder with an inflammatory reaction in the mucosa of the large intestine. The inflamed mucosa swells, becomes ulcerated and bleeds.
Crohn’s disease also features inflammation in the gut. Typical symptoms are prolonged diarrhoea, abdominal pain and sometimes weight loss.
3.4% of the participants were diagnosed with non-specific IBD.
In connection with the diagnosis, the doctors asked the patients simple questions as rapid screening for HS, including whether they periodically had abscesses and inflammation around the armpits, groin, buttocks and breasts.
If HS was suspected, they were referred for further examination by a dermatologist.
8% newly diagnosed with Crohn’s had HS
The results showed that 5.5% of those newly diagnosed with IBD also had HS, but the percentages differed according to the IBD.
8% of those diagnosed with Crohn’s disease had HS versus only 4% of those diagnosed with ulcerative colitis.
“The fact that 6% of those with IBD had HS is not surprising, but the fact that they already had it at the time of diagnosis is surprising. Further, many did not know that they had HS,” explains Johan Burisch.
The research also revealed that the people most ill with IBD and people with a higher body-mass index had HS more often.
People with IBD and HS may need more intensive treatment
Johan Burisch highlights several interesting aspects of the findings. The researchers determined the prevalence of HS among people newly diagnosed with IBD, and they identified several risk factors for HS among people with IBD, including disease severity, body-mass index and Crohn’s disease.
Johan Burisch says that another interesting point is that one of his previous studies showed that the more immune diseases a person has, the higher the risk of a poor illness trajectory.
“Since people with both IBD and HS are also more severely ill, we may need to consider this in our treatment choices and give them more intensive treatment early in the process,” he says.
Follow-up after five years
Johan Burisch says that another lesson is to use the diagnosis of IBD to screen for comorbid HS by asking a few questions and referring them to a dermatologist if necessary to reduce the diagnostic delay.
Further, this study is just the first step towards improving understanding of how HS affects the illness trajectory in IBD and vice versa.
“We need to think beyond the gut. IBDs are more than just manifestations in the gut, because they can be accompanied by skin disease. Now we aim to follow the patients over five years to determine the clinical implications of being diagnosed with both HS and IBD. In reducing the diagnostic delay for people with HS, our study suggests that screening for HS among people with IBD might make sense,” concludes Johan Burisch, who emphasises that gastroenterologists and dermatologists will also work together to investigate the mechanisms linking IBD and HS.
