Abstract: 【Abstract】 Objective To analyze clinical, immunopathological, therapeutic, and prognostic features of epidermolysis bullosa acquisita （EBA）. Methods A retrospective study was conducted on patients with confirmed EBA at the Department of Dermatology, West China Hospital, Sichuan University from January 1, 2015 to July 30, 2022. Their clinical, immunopathological, therapeutic and prognostic features were analyzed. The autoimmune bullous skin disorder intensity score （ABSIS） was used to assess the severity of lesions in patients with EBA, and the visual analogue scale （VAS） to assess itch intensity. Descriptive statistical analysis was primarily carried out, and the correlation between disease severity scores and itch scores was analyzed using Pearson correlation analysis. Results A total of 13 patients with EBA were included, including 9 males and 4 females, with the age at the clinic visit being 49.0 ± 20.6 years and ABSIS scores being 24.2 ± 10.7 points. One patient was diagnosed with classical EBA, while the remaining 12 patients with inflammatory EBA. Mucosal involvement was observed in 6 cases, whose oral mucosae were all affected. All patients had itching to varying degrees, with VAS scores of 5.6 ± 2.2 points; 9 of the 12 inflammatory EBA patients had VAS scores of ≥ 5 points, whereas 1 classical EBA patient had a VAS score of 2 points; there was no significant correlation between the ABSIS scores and VAS scores （r = -0.02, P > 0.05）. Histopathological examination showed subepidermal cleavages or blister formation and varying degrees of perivascular inflammatory cell infiltration in the superficial dermis of patients with inflammatory EBA. Direct immunofluorescence assay demonstrated linear IgG deposits along the basement membrane zone in all 13 patients, including 12 with concomitant linear C3 deposits in the basement membrane zone, 5 with linear IgA deposits, and 2 with IgM deposits. Indirect immunofluorescence on salt-split skin showed IgG deposition on the dermal side of the salt-split skin in the 13 patients. An elevated eosinophil count in the peripheral blood was observed in 1 out of 11 patients, while increased total IgE levels were noted in 3 out of 9 patients. Among the 13 EBA patients, 11 were treated with systemic glucocorticoids （equivalent to 10 - 100 mg/d of prednisone）, and the other 2 were treated with compound glycyrrhizin tablets, sulfasalazine, hydroxychloroquine sulfate, and minocycline hydrochloride alone or in combination. During the follow-up period of 34.0 （27.5, 66.0） months in the 13 patients, 8 achieved complete remission after drug withdrawal, 2 achieved complete remission on therapy, 1 achieved partial remission on minimal therapy, and 2 presented with uncontrolled condition. The time to complete remission off/on therapy was 6.0 （3.8, 17.5） months. Conclusions The inflammatory phenotype seems to be relatively common in EBA patients, with itching to varying degrees, and oral mucosa was the most commonly involved mucosa in those with mucosal damage. After treatment with systemic glucocorticoids alone or in combination with immunomodulators, most patients could achieve complete remission.

Key words: Epidermolysis bullosa acquisita, Skin diseases, vesiculobullous, Pruritus, Therapy, Prognosis