Successful Drug Desensitization to Ustekinumab in a Patient with Crohn's Disease

Ustekinumab is a monoclonal antibody used as treatment for various inflammatory conditions. We present a pediatric patient with Crohn's disease who did not tolerate infliximab and was then changed to ustekinumab. He developed anaphylaxis to the medication after the second dose. A drug desensitization protocol was created by the allergy team leading to successful administration of both intravenous and then subcutaneous ustekinumab. As monoclonal agents become mainstays of therapy for inflammatory conditions, there are increased reports of allergic reactions. Prior reports and protocols of ustekinumab desensitization have not been reported. This case report highlights successful desensitization to ustekinumab as well as the importance of a multidisciplinary approach to addressing treatment needs of patients who develop life-threatening reactions to such medications.