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Prevalence of IBD in Patients with Psoriasis

The prevalence of inflammatory bowel disease (IBD) among Japanese patients with psoriasis was 1.2%, a new study found. The cross-sectional study included 681 patients with psoriasis (449 men, 232 women). Information was collected regarding their current or prior history of Crohn’s disease (CD) or ulcerative colitis (UC). Researchers found:

  • Among 681 participants, only 8 (1.2%) had UC and 2 (0.3%) had CD.
  • Diagnosis of IBD preceded psoriasis in 5 patients, while diagnosis of psoriasis preceded IBD in 2 patients.
  • 70% of UC-positive patients had mild psoriasis, 20% had moderate psoriasis, and 10% had severe psoriasis.
  • There were no differences in age at onset of psoriasis, age at first visit or complications when UC-positive psoriatic patients were compared with IBD-negative psoriatic patients.
  • US-positive patients had significantly higher body mass index compared with patients without IBD.


Masaki S, Bayaraa B, Imafuku S. Prevalence of inflammatory bowel disease in Japanese psoriatic patients. [Published online ahead of print May 14, 2019]. J Dermatol. doi: 10.1111/1346-8138.14900.


In psoriasis patients the incidence rates of Crohn’s disease as well as ulcerative colitis have been increased in epidemiological studies. This study correlates with a previous study that looked at the incidence in the Danish population where < 1% of psoriasis patients developed Crohn’s disease or ulcerative colitis. Biologic agents that target tumor necrosis factor and interleukin-12/23 are approved for both psoriasis and Crohn’s disease. Such patients with both psoriasis and Crohn’s disease may benefit from these agents. Conversely, there is a very low rate of exacerbation or new onset of inflammatory bowel disease with biologics that target interleukin-17 and caution should be exercised if patients have both conditions. —Paul S. Yamauchi, MD, PhD; Clinical Assistant Professor of Dermatology David Geffen School of Medicine at UCLA; Harbor-UCLA Medical Center Division of Dermatology; Adjunct Associate Professor John Wayne Cancer Institute.