S2475 Exacerbation of Atopic Dermatitis Associated With Ustekinumab Treatment in Crohn’s Disease

Abstract

Introduction: Ustekinumab has been approved for moderate to severe Crohn’s disease (CD) and though binding the p40 subunit of interleukin(IL)-12 and IL-23, modulates the T-helper (Th) 2 pathway. This may exacerbate atopic diseases including atopic dermatitis (AD). Indeed, reports of AD exacerbations in psoriatic patients receiving ustekinumab do exist. However, no exacerbations in CD patients receiving ustekinumab have been reported. Case Description/Methods: We report a case of a 27-year-old female with a history of AD, seasonal allergies, hay fever, and CD. Diagnosed in 2004, she subsequently failed multiple biologic therapies. Ustekinumab and azathioprine were initiated in 2015. In 2016, she retained a capsule endoscopy and was noted to have a mid ileal stricture that was resected. Ustekinumab frequency was increased from eight to six weeks. In late 2016, her colonoscopy revealed Rutgeert’s i0 disease. However, in 2018 she had developed Rutgeertt’s i2 disease on her colonoscopy. In 2019, the ustekinumab frequency was increased to four weeks for three months. Her AD worsened, particularly after the injections, and no longer responded to topical agents. Allergy and Dermatology were consulted. Laboratory findings revealed peripheral eosinophilia and elevated serum IgE (sIgE). Severe exacerbation of AD was diagnosed. The ustekinumab frequency was increased to eight weeks. The patient’s AD improved and has remained controlled with topical agents and azathioprine. The eosinophilia resolved, however, sIgE was not re-evaluated. Her CD remains in remission. Discussion: This is the first reported case of patient with CD experiencing an exacerbation of underlying AD after receiving ustekinumab at a four-week frequency. The phase III (UNITI-1, UNITI-2) and phase IV (IM-UNITI) studies of ustekinumab in patients with CD do not report exacerbation of atopic diseases as an adverse event. However, ustekinumab was not administered at a four-week frequency either. Ustekinumab trough levels have been shown to increase with increased frequency of dosing. Cases of AD exacerbation associated with ustekinumab have been reported in patients with psoriasis. The exacerbations resolved with ustekinumab discontinuation. We hypothesize atopic history increased susceptibility to a Th2 response and ustekinumab augmented the response when given more frequently. Her AD then improved due to decreased ustekinumab infusion frequency. In conclusion, ustekinumab may worsen AD severity in CD patients with a history of atopy.