Abstract: 【Abstract】 Objective To analyze clinical features of coronavirus disease 2019 in patients with autoimmune blistering diseases （AIBDs）, and to explore risk factors for the development of severe coronavirus disease 2019 in patients with AIBDs. Methods Clinical data were collected from patients with AIBDs who were hospitalized in Zhongda Hospital, Southeast University from August 2021 to December 2022, and were retrospectively analyzed. Independent sample t-test, Mann-Whitney U test, or chi-square test （Fisher′s exact test） were used to analyze factors associated with severe coronavirus disease 2019 in AIBD patients. Results A total of 30 patients with AIBDs accompanied by coronavirus disease 2019 were included, they were aged 62.90 ± 15.72 years, and included 16 males and 14 females; pemphigus vulgaris （12 cases, 40.00%） and bullous pemphigoid （13 cases, 43.33%） predominated in the disease spectrum of AIBDs in these patients. The common clinical manifestations of coronavirus disease 2019 were cough （25 cases, 83.33%）, fatigue （22 cases, 73.33%）, and fever （15 cases, 50.00%）; most patients had mild clinical symptoms, while 7 （23.33%） developed into severe coronavirus disease 2019, including 2 out of 14 aged 30 - 59 years and 5 out of 16 elderly patients aged ≥ 60 years, and 2 out of the 5 elderly patients finally died. According to the clinical classification criteria of coronavirus disease 2019, the 30 patients were divided into the mild-to-moderate group （23 cases） and severe group （7 cases）; the duration of AIBDs was significantly shorter in the severe group （10.71 ± 10.72 months） than in the mild-to-moderate group （27.61 ± 19.67 months, t = 2.16, P = 0.040）; the remission rate of AIBDs was significantly higher in the mild-to-moderate group （21/23） than in the severe group （4/7, χ2 = 4.36, P = 0.037）; the average daily dosage of methylprednisolone during the last month was significantly lower in the mild-to-moderate group （M［Q1, Q3］: 8 ［4, 14］ mg） than in the severe group （24 ［12, 47］ mg, U = 133.50, P = 0.007）, and the proportion of patients treated with methylprednisolone at an average dosage of > 8 mg was significantly higher in the severe group （6/7） than in the mild-to-moderate group （8/23, χ2 = 5.59, P = 0.031）. Conclusions Among the patients with AIBDs accompanied by coronavirus disease 2019, the incidence and mortality of severe coronavirus disease 2019 were higher in elderly patients than in young patients. The short course and no-remission of AIBDs, and the average daily dosage of methylprednisolone being＞8 mg/d during the last month were risk factors for the development of severe coronavirus disease 2019 in the patients with AIBDs.

Key words: Skin diseases, vesiculobullous, Autoimmune diseases, Risk factors, COVID-19, Clinical features