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: IgA Vasculitis For further information, see CMDT Part 22-14: Nephritic Spectrum Glomerular Diseases + Key Features Download Section PDF Listen +++ ++ Formerly called Henoch-Schönlein purpura Systemic small-vessel leukocytoclastic vasculitis associated with IgA subclass 1 deposition in vessel walls The most common systemic vasculitis in children; often associated with an inciting infection, such as group A streptococcus Occurs in adults as well Classic presentation is with palpable purpura + 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 A decrease in GFR is common with a nephritic presentation Renal lesions can be identical to those found in IgA nephropathy Most patients with microscopic hematuria and minimal proteinuria recover fully over several weeks Progressive CKD and possibly ESRD are more likely to develop in those with the nephrotic syndrome; the presence of both nephritic and nephrotic syndrome features poses the worst renal prognosis + 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 Rituximab treatment and plasma exchange have been successful for severe nephritic disease according to case reports, but clinical trials are lacking Rapidly progressive renal disease with crescent formation on biopsy may be treated as in ANCA-associated vasculitis