Unraveling the Link Between Bullous Pemphigoid and Neurological Disease: A Single-center Study of 257 Patients.

Background: Multiple studies have corroborated the association between bullous pemphigoid (BP) and neurological diseases; patients with both diseases (BP-N) have been associated with a worse prognosis and specific clinical and immunological characteristics, defining a different subtype of BP.

Objectives: We aimed to determine the prevalence and characteristics of BP cases with neurological comorbidities (BP-N) and review the related published literature.

Methods: We conducted a retrospective, observational study of BP cases treated at a referral center for autoimmune blistering diseases from January 2000 through June 2020.

Results: We collected epidemiological, clinical, histopathological, progression and laboratory data from a total of 257 cases, 102 of which were BP-N. Senile dementia, Alzheimer's disease and vascular dementia were the most frequent neurological comorbidities. Compared with cases without neurological comorbidities, BP-N cases had more intense tissue eosinophilia (P=.012) and higher concentrations of circulating eosinophils (P=.000), and anti-BP180 IgG antibodies (P=.007). At the time of data collection, 78 BP-N were deceased.

Conclusions: Our case series highlighted the relevance of neurological comorbidities in BP patients; although the pathogenesis is still to be elucidated, the neuroinflammation present in neurodegenerative diseases could explain the neurocutaneous link and the chronological relationship between these entities.