[A case of Crohn's disease complicated by Guillain-Barrè syndrome during ustekinumab therapy].

We herein report a case involving a 23-year-old male patient with active Crohn's disease complicated by Guillain-Barrè syndrome during ustekinumab therapy. At age 11, the patient developed an anal fistula and was found to have multiple aphthae on the rectosigmoid colon, for which he was diagnosed with Crohn's disease. At age 12, he underwent gastrojejunal anastomosis for pyrolic stenosis. At age 20, a longitudinal ulcer was found on the ascending colon, and at age 21, aphthae were found on the stomach and efferent jejunum. At age 22, adalimumab was started, but the patient noted abdominal pain and diarrhea 4 months later. Hence, adalimumab was switched to ustekinumab (2017 June). Though ustekinumab was effective, the patient noted anorexia, weakness, and bilateral lower extremity numbness 1 year later (2018 June) and was admitted to the hospital. He was then diagnosed with Guillain-Barrè syndrome after spinal tap, neurological, and hematological examinations. Immunoglobulin therapy was provided but was less effective. The patient has since been receiving physical therapy. This has been the first report regarding Guillain-Barrè syndrome as a complication during ustekinumab therapy.