Bullous pemphigoid preceding the diagnosis of colorectal adenocarcinoma.

Bullous pemphigoid (BP) is a rare autoimmune skin disorder most commonly seen in older adults. It is marked by subepidermal blistering due to autoantibodies targeting hemidesmosomal proteins. While often idiopathic, BP has occasionally been linked to internal malignancies. We present the case of a 77-year-old man whose diagnosis of BP led to the detection of invasive colorectal adenocarcinoma. This case highlights the need for malignancy screening in patients with atypical dermatologic presentations and systemic symptoms.