Bullous Pemphigoid and Malignancy in Two Different Hospital Populations: A Retrospective Cohort Review

Background: Bullous pemphigoid (BP) is a rare autoimmune blistering condition characterized by antibodies to the structural proteins BP1 and BP2 at the dermal-epidermal junction. The link between BP and malignancy remains unclear. Due to the rarity of the disease, there have been few studies with small sample sizes characterizing the association between BP and malignancy. Objectives: There were two main goals of this retrospective cohort study: (1) to look at the associated risk of malignancy in patients with BP compared to controls and (2) to compare the rates of malignancy in two separate hospitals with differing patient populations. Method: We reviewed the medical records of 99 patients diagnosed with BP observed between 2014 and 2019. 66 patients were from Keck Hospital and 33 were from Los Angeles County/University of Southern California (LAC/USC) Hospital. Each patient was age- and sex-matched to a control from the same hospital. Results: Malignancies occurred in 26 BP patients and 29 controls. 7 of the BP patients from LAC/USC Hospital (21.2%) and 19 patients from Keck Hospital (28.8%) had malignancies. Conclusions: Overall, we did not find an increased risk of malignancy in BP patients compared to controls, nor did we find a statistically differing rate of malignancy in BP patients from various socioeconomic and ethnic backgrounds.