109 A Rare Cutaneous Drug Reaction Associated With Risankizumab Use

Background: Crohn's disease (CD) is a chronic inflammatory condition affecting the gastrointestinal tract. characterized by gastrointestinal inflammation. Risankizumab (RZA) was approved by the food and drug administration in 2022 for the treatment of moderately to severely active CD. Phase 3 trials have demonstrated the safety of RZA with 1%–2% reporting an infusion-related reaction. We present a case of a severe dermatologic reaction after RZA exposure in patient with CD. Case Presentation: A 69-year-old male diagnosed with jejunoileal CD in 1968 with perianal involvement status post multiple small bowel resection and Roux-en-Y gastric bypass, ankylosing spondylitis initiated on RZA every 8 weeks for management of CD. He tolerated the first infusion; however, he developed a pruritic rash after the second infusion that resolved following a short course of oral steroids. The third infusion resulted in an extensive papular eruption on the chest and upper back shortly after infusion. Patient used moisturizing cream with some improvement, but the rash still persisted on his chest and back as blisters with hemorrhagic crusted papule on right chest. The patient has no history of dermatologic condition or previous drug reaction. Physical examination showed multiple diffuse erythematous monomorphic papules within a background of erythema on the chest and upper back. An erythematous papule with hemorrhagic crusting on the right chest. Multiple hypopigmented macules on the bilateral upper extremities. Punch biopsy consistent with acute to subacute spongiotic dermatitis with superficial perivascular eosinophils. These changes can be seen in drug reactions, atopic dermatitis (eczema), or allergic contact dermatitis. Dermatology felt that there are 2 plausible causes of this rash occurring after RZA including RZA-induced atopic dermatitis or RZA-induced drug reaction. Treatment included drug avoidance (RZA) and topical corticosteroid cream, resulting in significant improvement of skin lesions. Conclusions: This is a case report of a rare skin reaction due to RZA in patient with CD, adding to the limited case reports in patients on RZA. The mechanism of reaction is unclear. A prior report of 2 patients developing pluritic erythematous plaques after RZA responded to topical corticosteroids with interesting finding of elevated IgE level in both patients. It is important to recognize possible dermatologic manifestations on IBD treatments including those initiated on RZA.