Thematic Evolution and Diversification of Bullous Pemphigoid Research: A Bibliometric Analysis, 1959-2025

Bullous pemphigoid research spans autoantigen and basement membrane biology, diagnosis, comorbidity, inflammatory pathways, and treatment, but its long-term conceptual development has not been mapped.

English-language articles and reviews indexed in the Science Citation Index Expanded through December 31, 2025, were retrieved from title, author-keyword, and abstract fields. Records underwent AI-assisted first-pass screening followed by human review. Bibliometrix and VOSviewer were used for parameter-tested author-keyword clustering and a full-corpus title-term sensitivity analysis.

Of 3,471 screened records, 2,121 were eligible. Annual output accelerated after 2015 and exceeded 100 publications in 2022, 2023, and 2025. Author keywords were available for 55.1% of publications. The selected network contained 112 keywords, 889 links, and eight clusters. Among 924 keyword-mappable publications, autoantigens, autoantibodies, and basement membrane zone biology declined from 51.9% in 1959-1998 to 14.6% in 2021-2025. Therapeutic management and clinical outcomes increased from 7.7% to 37.8%, epidemiology and comorbidities from 1.9% to 20.8%, dipeptidyl peptidase-4 inhibitor-associated bullous pemphigoid from 0% to 12.7%, and immune checkpoint inhibitor-associated bullous pemphigoid from 0% to 10.8%. Diagnosis and related autoimmune blistering diseases peaked at 50.0% in 1999-2013 before declining to 24.3%. Inflammatory and immune effector mechanisms showed no statistically significant period variation after multiplicity adjustment. The title-term analysis recovered the major domains.

Bullous pemphigoid research diversified from structural, immunological, and diagnostic foundations toward treatment, clinical outcomes, comorbidity, and medication-associated disease. Although author-keyword availability was incomplete and varied substantially over time, the findings provide a longitudinal map of the field, with temporal estimates reflecting relative prominence within keyword-mappable publications.