Adult-onset Still’s disease (AOSD) is an acute systemic inflammatory disease with unknown etiology and pathogenesis. Fever together with skin, musculoskeletal, and rarely cardiopulmonary and reticuloendothelial system involvements are prominent findings. Renal involvement is much rarer. Herein, we report a case of a patient, who presented with classical findings of AOSD and microscopic hematuria, and was histologically diagnosed as IgA nephropathy. A twenty-four-year-old male attended to our clinic with arthralgia, fever, rash and darkening of urine color for the last two months. Physical examination was normal, except for fever of 39.3 oC, diffuse maculopapular rash and arthritis. Laboratory tests of the patient, who had macroscopic hematuria, revealed leukocytosis with neutrophil predominance and elevated erythrocyte sedimentation rate, CRP and ferritin (>2000 ng/ml) levels. ANCA, ANA and RF were negative. After excluding diseases associated with systemic vasculitis, he was diagnosed as AOSD according to the above-mentioned clinical and laboratory findings and steroid treatment was initiated. Renal biopsy performed due to persistent hematuria and proteinuria was consistent with IgA nephropathy. Renal involvement in AOSD is usually in the form of microscopic hematuria and transient proteinuria. Persistant macroscopic hematuria in spite of treatment is not expected in AOSD. In this situation, other co-existing renal diseases should be sought, and renal biopsy should be done when necessary.
Keywords: Adult-onset Still’s disease, hematuria, IgA nephropathy