Childhood-onset bullous systemic lupus erythematosus.

Bullous systemic lupus erythematosus has rarely been described in pediatric lupus population and the real prevalence of childhood-onset bullous systemic lupus erythematosus has not been reported. From January 1983 to November 2013, 303 childhood-onset SLE (c-SLE) patients were followed at the Pediatric Rheumatology Unit of the Childreńs Institute of Hospital das Clínicas da Faculdade de Medicina Universidade da Universidade de São Paulo, three of them (1%) diagnosed as childhood-onset bullous systemic lupus erythematosus. All three cases presented tense vesiculobullous lesions unassociated with lupus erythematosus lesions, with the median duration of 60 days (30-60). All patients fulfilled bullous systemic lupus erythematosus criteria. Two had nephritis and serositis and presented specific autoantibodies. The histological pattern demonstrated subepidermal blisters with neutrophils-predominant infiltrates within the upper dermis. Direct immunofluorescence (DIF) showed deposits of IgG and complement along the epidermal basement membrane, in the presence or absence of IgA and/or IgM. A positive indirect immunofluorescence on salt-split skin demonstrating dermal binding was observed in two cases. All of them had moderate/severe disease activity at diagnosis with median Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) of 18 (14-24). Two patients received dapsone and one with severe nephritis received immunosuppressive drugs. In conclusion, in the last 30 years the prevalence of bullous lupus in childhood-onset lupus population was low (1%) in our tertiary University Hospital. A diagnosis of SLE should always be considered in children with recurrent tense vesiculobullous lesions with or without systemic manifestations.