Systemic lupus erythematosus with severe nephritis that mimicked Henoch-Schoenlein purpura.

INTRODUCTION: Systemic lupus erythematosus (SLE) belongs to a family of related autoimmune rheumatic disorders that are capable of affecting multiple organs, and they are all associated with a variety of autoantibodies. Henoch Schoenlein purpura (HSP) is a sort of systemic vasculitis that is not associated with auto-antibodies and can affect different organs including the kidneys. CASE REPORT: A 12 year-old girl presented with abdominal pain, low grade fever, swollen and tender feet and left hand, skin rash on the lower extremities, and high blood pressure. Initial laboratory tests revealed severe proteinuria, microscopic hematuria and low C3 level. Renal biopsy showed diffuse proliferative glomerulonephritis with IgA, fibrinogen and C3 deposits. The case was accordingly diagnosed as HSP with severe IgA nephropathy. Treatment was started with mycophenolate mofetil (MMF) and pulse methylprednisolone followed by prednisolone. The patient improved and treatment was discontinued after 5.5 months. One month after withdrawal of her medications, the patient presented again with serositis and recurrent proteinuria. Both antinuclear antibodies (ANA) and anti dsDNA were positive. At this point she was diagnosed to have SLE disease and immunosuppressive treatment was restarted. Following this, symptoms disappeared, proteinuria regressed and anti-dsDNA titer dropped.
CONCLUSION: This case presented with features of HSP and was later-on diagnosed to have SLE. This kind of clinical overlapping has not been reported in the literature to the best of our knowledge.