Hospitalization and mortality in Asian autoimmune bullous dermatosis patients: A 17‐year retrospective study

Abstract Limited data exist on the factors associated with hospitalization and mortality in Asian inpatients with autoimmune bullous dermatoses (AIBDs). This study aimed to elucidate the risk factors affecting hospitalization and mortality rates in Asian patients with AIBDs. A retrospective analysis of patients with AIBDs treated at Siriraj Hospital during a 17‐year period was performed using the International Classification of Diseases 10th revision codes. The characteristics of inpatients and outpatients were compared, and mortality rates and associated factors were identified. The study included 360 AIBD patients (180 inpatients, 180 outpatients). Inpatients were significantly younger than outpatients. The identified risk factors for hospitalization were malignancy (odds ratio [OR] 2.83, 95% confidence interval [CI] 1.13–8.04; p = 0.034), moderate to severe disease (OR 2.52, 95% CI 1.49–4.34; p < 0.001), systemic corticosteroid use ≥15 mg/day (OR 2.27, 95% CI 1.21–4.41; p = 0.013) and oral cyclophosphamide treatment (OR 9.88, 95% CI 3.82–33.7; p < 0.001). Kaplan–Meier analysis revealed mortality rates of 26%, 36% and 39% for inpatients with pemphigus at 1, 3 and 5 years, respectively. For inpatients with pemphigoid, the corresponding rates were 28%, 38% and 47%. Infections, particularly pneumonia, were the predominant cause of death in both conditions. This study confirmed that both Asian ethnicity and healthcare disparities may be correlated with adverse outcomes in patients with AIBDs. Pemphigus mortality rates were substantially greater in Asian patients than in Caucasian patients. Continuous monitoring of factors contributing to hospitalization and mortality is imperative to improve treatment outcomes.