Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 20-25: Henoch-Schönlein Purpura + Key Features Download Section PDF Listen +++ ++ The most common systemic vasculitis in children Occurs in adults as well + Clinical Findings Download Section PDF Listen +++ ++ Purpuric skin lesions typically located on the lower extremities; may also be seen on the hands, arms, trunk, and buttocks Joint symptoms are present in most patients; the knees and ankles are most commonly involved Abdominal pain secondary to vasculitis of the intestinal tract is often associated with gastrointestinal bleeding Hematuria signals the presence of a glomerular lesion that is usually reversible, although it occasionally may progress to chronic kidney disease + Diagnosis Download Section PDF Listen +++ ++ Skin biopsy can demonstrate leukocytoclastic vasculitis with IgA deposition Kidney biopsy reveals segmental glomerulonephritis with crescents and mesangial deposition of IgA Differential diagnosis Immune thrombocytopenia Meningococcemia Rocky Mountain spotted fever Rheumatoid arthritis (including juvenile form) Polyarteritis nodosa Endocarditis Cryoglobulinemia + Treatment Download Section PDF Listen +++ ++ Chronic courses with persistent or intermittent skin disease are more likely to occur in adults than children The efficacy of treatment is not well established In children, prednisone (1–2 mg/kg/day orally) does not decrease the frequency of proteinuria 1 year after onset of disease Severe disease is often treated with aggressive immunosuppressive agents such as mycophenolate mofetil, but there is no consensus as to the efficacy of this approach or the optimal therapeutic regimen