Abstract
Bullous pemphigoid (BP) is a complex autoimmune blistering disease with an increased incidence in the comorbid population, particularly among older adults. The occurrence of drug-induced BP is associated with an underlying genetic predisposition, triggering an enhanced immune response, the formation of autoantibodies, and alterations in antigenic properties within the basement membrane zone. With over 90 identified drugs capable of precipitating BP, we present the case of an 87-year-old woman with comorbidities who experienced a medication change from losartan to sacubitril/valsartan. Three months later, erythematous lesions appeared on her lower limbs, progressing to a generalized rash accompanied by itching. Over the following month, these lesions evolved into tense blisters with serous content and intense pain. Suspecting the medication switch to sacubitril/valsartan as the cause, the drug was discontinued, and immunomodulatory treatment was initiated, resulting in a notable improvement in the lesions.