Resolution of alopecia areata after switching from vedolizumab to ustekinumab in a patient with Crohn’s disease: a case report

Background Crohn’s disease (CD) is a chronic inflammatory bowel disease that can be associated with extraintestinal manifestations. Alopecia areata (AA) is an autoimmune non-scarring hair loss disorder. Their coexistence is uncommon, and managing both conditions simultaneously is challenging when intestinal and cutaneous responses diverge. Ustekinumab, a monoclonal antibody targeting the shared IL-12/IL-23 pathway, may offer a dual therapeutic benefit, but evidence in comorbid cases is limited. Case introduction We report an 18-year-old man with a 2-year history of recurrent paroxysmal abdominal pain and mucoid hematochezia, as well as patchy non-scarring scalp alopecia. Computed tomography enterography and colonoscopy showed segmental bowel wall thickening and diffuse pinpoint erosions; histopathological examination demonstrated non-caseating granulomas, supporting a diagnosis of CD. Vedolizumab induction therapy with methylprednisolone bridging resulted in disease remission. The patient’s hair loss persisted, and he was diagnosed with AA. After his AA failed to respond to topical corticosteroids, his treatment was switched from vedolizumab to ustekinumab (390 mg intravenously at week 0, followed by 90 mg subcutaneously every 8 weeks). By week 24, marked scalp hair regrowth was evident, and by week 48, complete resolution of AA was achieved, while his CD remained in remission. Conclusion This case suggests that ustekinumab may be a feasible therapeutic option for patients with coexisting CD and refractory AA, particularly when a shared IL-12/IL-23-mediated inflammatory pathway is suspected. Further prospective studies are required to confirm its efficacy and generalizability in this setting.