Effective use of switching biologics for ulcerative colitis complicated with pyoderma gangrenosum and primary sclerosing cholangitis.

Although prednisolone, granulocyte/monocyte apheresis, calcineurin inhibitor and anti-tumour necrosis factor (TNF) therapy are generally used, no treatment strategy for inflammatory bowel disease complicated with pyoderma gangrenosum (PG) has been established yet. Herein, we present the case of a 29-year-old man with ulcerative colitis (UC) complicated with primary sclerosing cholangitis. When UC relapsed and PG developed, prednisolone and granulocyte/monocyte apheresis were used; however, their therapeutic effects were deemed insufficient. After 2 weeks, adalimumab (ADA) induced remission; however, his UC and PG relapsed 20 weeks later. As a result of switching to infliximab, since a loss of response to ADA was deemed to have occurred, remission was reintroduced and subsequently maintained for 40 weeks. We conclude that anti-TNF-α antibodies might be selected as the first choice when PG and UC are refractory to treatment, and a switch to anti-TNFs should be considered when the effect is still insufficient.