Clusters of clinical and immunologic features in patients with bullous systemic lupus erythematosus: experience from a single-center cohort study in China

BACKGROUND: Bullous systemic lupus erythematosus (BSLE) is a rare subtype of systemic lupus erythematosus (SLE) that is clinically characterized by subepidermal tense vesicles or bullae. We aimed to investigate the clinical and laboratory features of patients with BSLE. METHODS: We retrospectively reviewed all patients who fulfilled the diagnostic criteria for BSLE in our institution from 2015 to 2021. Cutaneous lesions, systemic manifestations, treatment options, and outcomes were evaluated. For each case of BSLE, four controls were randomly selected from patients with single SLE. Major clinical and laboratory characteristics were compared between the two groups. RESULTS: Among 4221 patients with SLE, 12 developed BSLE. Vesiculobullous lesions were the first sign in five of the BSLE patients (5/12, 41.7%) and appeared after SLE diagnosis in the remaining seven patients (7/12, 58.3%), with a median duration from SLE onset of 36 months (4–115 months). The most common BSLE-affected sites were the head and neck (10/12, 83.3%), extremities (9/12, 75.0%), trunk (7/12, 58.3%), and mucosae (6/12, 50.0%). All patients with BSLE had extra-cutaneous involvement. The SLE disease activity index score exceeded 5 in 10/12 (83.3%) patients, which indicated high disease activity. Patients in the BSLE group had significantly higher incidences of proteinuria (83.3% vs. 47.9%, P = 0.027), hematuria (75% vs. 31.3%, P = 0.006), hemolytic anemia (33.3% vs. 0%, P = 0.000), and leukopenia (66.7% vs. 25.0%, P = 0.006) than those in the control group. The use of systemic corticosteroids, immunosuppressants, dapsone, and skin care was effective in controlling disease. CONCLUSIONS: Vesiculobullous lesions may be the first manifestation and indicate a high disease activity in patients with BSLE. Early diagnosis using clinical, histopathological, and immunological evaluations can lead to appropriate treatment of this progressive disease and improve prognosis.