Association between inflammatory bowel disease and pruritus

Abstract

Background: Inflammatory bowel disease (IBD) is often complicated by extraintestinal manifestations. We frequently encounter IBD patients with pruritus; however, clinical evidence for the association of these conditions is lacking. Therefore, the present study investigated the incidence of pruritus in IBD patients. Methods: Seventy-one IBD outpatients, including 55 with ulcerative colitis (UC) and 16 with Crohn disease, and 39 healthy volunteers (HVs) were surveyed about their pruritus symptoms using a visual analogue scale (VAS). Disease activities in UC and Crohn disease patients were classified according to partial Mayo and IOIBD (International Organization for the Study of inflammatory Bowel Disease) scores, respectively. Skin barrier condition was examined by measuring transepidermal water loss and stratum corneum hydration. The distribution of intraepidermal nerve fibers in skin samples from 9 UC patients was examined immunohistochemically using an antiprotein gene product (PGP) 9.5 antibody. Results: Visual analogue scale scores were higher in IBD patients than in HV (P < 0.001). Active stage IBD patients had more severe pruritus VAS scores than those in the remission stage (P = 0.036). Transepidermal water loss was higher in IBD patients (P < 0.001) and active stage IBD patients (P = 0.004), while stratum corneum hydration was lower in IBD patients (P = 0.019) and active stage IBD patients than in HV (P = 0.019). A relationship was observed between the degree of pruritus and number of PGP9.5-immunoreactive intraepidermal nerve fibers in UC patients. Conclusions: Inflammatory bowel disease patients, particularly active stage patients, frequently exhibit symptoms of pruritus and dry skin. This result may have predictive and therapeutic implications for the treatment of IBD symptoms. Lay Summary This study examined the skin symptoms of inflammatory bowel disease patients. As results of statistical analyses, they were associated with symptoms of pruritus and dry skin. These findings suggest that inflammatory bowel disease may be related to skin barrier dysfunction.