Cutaneous autoimmune blistering disease during mirikizumab therapy in a patient with ulcerative colitis: a new potential trigger?

Autoimmune blistering diseases (AIBDs) may occur as adverse effects of various therapies, including biologics. Data on their association with IL-23 inhibitors in ulcerative colitis (UC) remain limited. We report the case of a 59-year-old man with UC who developed pruritic cutaneous bullae emerging within days following mirikizumab infusion. Histopathological examination and direct immunofluorescence demonstrated findings consistent with an AIBD. Following the withdrawal of mirikizumab, the resid