Ustekinumab as a Treatment for Ixekizumab-Associated New-Onset Crohn's Disease in a Patient with Psoriasis.

Interleukin-17 inhibitors are effective treatments for plaque psoriasis. However, these medications have been linked to the development of new-onset inflammatory bowel disease (IBD) and the worsening of existing IBD in some patients. This case report describes a patient with plaque psoriasis who developed new-onset Crohn's disease after treatment with ixekizumab, an interleukin-17A inhibitor. He was then transitioned to ustekinumab, which resulted in successful remission of both psoriasis and Crohn's disease. This case highlights the potential for ustekinumab to be an effective rescue treatment for psoriasis patients with new-onset IBD triggered by medications.