IgA Vasculitis

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

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

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

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