Bullous lupus as the first manifestation of systemic lupus erythematosus in the pediatric population: A diagnostic challenge in daily practice

Introduction In the GLADEL cohort, the bullous lupus (BSLE) prevalence was 0.41%. However, literature on pediatric BSLE is scarce. This study described the clinical, histological, and immunological characteristics and the treatment response in a series of children with BSLE as the first clinical manifestation of pediatric SLE. Methods The clinical, histological, and immunological characteristics of a series of 5 cases of BSLE between 2010-2019 from two reference centers in Colombia were analyzed. Results All cases had bullous lesions that resolved with residual hypopigmentation. One had a focal seizure, and another arthritis with thrombocytopenia. Two had transient proteinuria with normal urinalysis. Anti-nuclear antibody titers ranged from 1:160 to 1:2560, and four were anti-dsDNA (+). Five patients had anti-RNP antibodies, and four anti-Sm antibodies. All had low C3, and 80% low C4 counts; 80% had erythrocyte sedimentation rate (ESR) >= 20 mm/hour and 60% had C-reactive protein (CRP) >= 0.5 mg/dL. All patients responded to glucocorticoids and dapsone. Histology reports and direct immunofluorescence (DIF) test showed subepidermal blisters with neutrophils in the papillary dermis and linear deposits of Igs/complement proteins in 80% of the skin biopsies. IgG/IgM was present in 5 samples. IgA was positive in 60% and C3 in 80%. Conclusions In this pediatric series, BSLE tends to have a monophasic behavior associated with neuropsychiatric, skeletal, and hematological involvement in 40% of the patients, and with good prognosis.