Retrospective Analysis of Clinical and Immunoserological Features in 86 Cases of Anti‐p200 Pemphigoid

Background Anti‐p200 pemphigoid is a rare autoimmune blistering disorder with limited data from China. This retrospective study aimed to investigate the clinical and serological characteristics of anti‐p200 pemphigoid to enhance disease understanding. Methods We analysed 86 confirmed anti‐p200 pemphigoid patients, evaluating their clinical manifestations, histopathological findings, and immunoserological profiles. Results The patients had a mean onset age of 56.92 ± 18.59 years and a male‐to‐female ratio of 2.31:1. The clinical presentation is highly heterogeneous, mimicking classic BP (57/86, 66.28%), and four cases (4/52, 7.69%) had concurrent psoriasis. Subepidermal blistering with variable dermal infiltrates was observed in 68 cases (68/70, 97.14%): neutrophil‐predominant (24.89%), mixed neutrophilic/eosinophilic (31.43%), or eosinophil‐predominant (27.14%). The positive rates of DIF, ss‐IIF, IB with dermal extract, and IB with laminin γ1 C‐terminal domain (LNγ1C) were 94.29% (66/70), 80.23% (69/86), 100% (86/86), and 64.29% (45/70), respectively. Conclusions Anti‐p200 pemphigoid closely resembles BP clinically but exhibits distinct immunopathological features. The partial reactivity to laminin γ1 (LNγ1) implies antigenic heterogeneity, warranting further investigation.