What is the appropriate management for a pediatric patient with IgA Vasculitis (IgAV) presenting with petechial rashes, scrotal edema, and impaired renal function following an appendectomy?

Management of Pediatric IgA Vasculitis with Renal Involvement and Scrotal Edema Post-Appendectomy

This pediatric patient with IgA Vasculitis presenting with active renal impairment requires immediate initiation of systemic corticosteroids, specifically oral prednisone/prednisolone or pulsed intravenous methylprednisolone, as the cornerstone of therapy for moderate to severe IgA vasculitis nephropathy (IgAVN) in children. 1

Immediate Therapeutic Intervention

Corticosteroid Therapy for Renal Protection

• Initiate glucocorticoids promptly for children with IgAVN presenting with biochemical evidence of renal impairment, as this patient demonstrates. 1
• The KDIGO 2021 guidelines specifically recommend oral prednisone/prednisolone or pulsed intravenous methylprednisolone for children with mild or moderate IgAVN. 1
• For rapidly deteriorating kidney function or nephrotic syndrome, children with IgAVN should be treated with the same aggressive regimen used for rapidly progressive IgA nephropathy, which may include cyclophosphamide and glucocorticoids. 1

Scrotal Involvement Management

• The scrotal edema with "cobblestone" ultrasonographic appearance represents testicular vasculitis, a recognized but underreported manifestation of IgAV that affects treatment decisions and follow-up intensity. 2
• Scrotal involvement in IgAV typically responds to systemic corticosteroid therapy without requiring additional urological intervention beyond monitoring. 2, 3
• Serial scrotal examinations and ultrasonography should be performed to monitor response, as testicular involvement can indicate more severe systemic disease. 2

Supportive Care and Monitoring

Renal Function Surveillance

• Urinalysis should be performed at each clinical visit to screen for progression of renal involvement, as the majority of IgAV children who develop nephritis do so within 3 months of presentation. 1
• Monitor serum creatinine, estimated glomerular filtration rate (eGFR), and proteinuria every 1-3 months during active disease. 1
• Consider renal biopsy if renal function fails to improve or continues to deteriorate despite corticosteroid therapy, as histopathological findings guide escalation of immunosuppression. 1

Post-Surgical Considerations

• The appendectomy performed 8 days prior was likely unnecessary, as GI symptoms preceded the rash in this case—a presentation occurring in 15-25% of IgAV cases where vasculitic ileitis mimics acute appendicitis. 1
• Routine interval appendectomy is not recommended after successful non-operative management of appendiceal complications in children, with recurrence rates of only 12-24%. 1
• Monitor for post-operative complications, though the surgical intervention itself does not alter IgAV management. 1

Escalation Strategy for Severe or Refractory Disease

When to Intensify Immunosuppression

• If the patient demonstrates rapidly progressive glomerulonephritis (RPGN) with extensive crescent formation (>50% of glomeruli), treatment should escalate to cyclophosphamide combined with glucocorticoids, following protocols used for ANCA-associated vasculitis. 1
• Children with nephrotic syndrome and/or rapidly deteriorating kidney function require the same aggressive approach as rapidly progressive IgAN. 1
• Plasma exchange may be considered in cases with life-threatening or organ-threatening extrarenal complications, though evidence is limited to uncontrolled case series. 1

Alternative Immunosuppressive Agents

• For glucocorticoid-sparing or in cases requiring additional immunosuppression, mycophenolate mofetil, cyclosporine A, or tacrolimus have shown favorable results in adult series and may be extrapolated to severe pediatric cases. 4, 5
• Rituximab has demonstrated efficacy in reducing relapse frequency and achieving long-term remission in both children and adults with severe IgAV, particularly when conventional therapy fails. 4, 6

Critical Pitfalls to Avoid

Do Not Confuse with Drug-Induced Vasculitis

• This is NOT drug-induced leukocytoclastic vasculitis, which would require only drug withdrawal without immunosuppression. 7
• The post-operative timing is coincidental; IgAV commonly follows upper respiratory infections and the surgical stress may have unmasked underlying disease. 3
• Drug-induced vasculitis typically presents with high-titre MPO ANCA or dual ANCA positivity, which is not characteristic of IgAV. 7

Avoid Prophylactic Corticosteroids for Isolated Extrarenal Disease

• Glucocorticoids should NOT be used to prevent nephritis in patients with isolated extrarenal IgAV (Grade 1B recommendation). 1
• However, this patient already has established renal impairment, making corticosteroids clearly indicated. 1

Do Not Apply Adult ANCA-Vasculitis Guidelines

• The EULAR/ERA-EDTA recommendations for ANCA-associated vasculitis management do not apply to pediatric IgAV, which follows distinct pathophysiology and treatment paradigms. 1
• IgAV is an IgA1-immune complex-mediated vasculitis, not an ANCA-associated vasculitis, despite both affecting small vessels. 3

Long-Term Prognosis and Follow-Up

Monitoring Duration

• Long-term follow-up extending beyond 3 months is essential, as renal involvement determines prognosis and can evolve over time. 1, 3
• The short-term outcome depends on gastrointestinal manifestation severity, while long-term prognosis hinges on nephritis severity. 3
• Approximately 10-30% of patients with IgAVN may progress to chronic kidney disease, though this risk is lower in children than adults. 4, 5

Relapse Surveillance

• Structured clinical assessment rather than laboratory testing alone should guide treatment decisions during follow-up. 1
• Recurrence of purpura, abdominal pain, or worsening renal parameters warrants prompt re-evaluation and potential treatment intensification. 3, 4