What are the potential complications of Henoch-Schönlein Purpura (HSP) in a pediatric patient?

Complications of Henoch-Schönlein Purpura in Pediatric Patients

Renal involvement is the most critical complication of HSP, occurring in 20-54% of children and representing the primary determinant of long-term morbidity and mortality. 1, 2

Renal Complications

Nephritis is the most important prognostic factor and can range from mild hematuria to severe crescentic glomerulonephritis with renal failure. 1, 2

• Mild manifestations include microscopic hematuria and mild proteinuria, which are common and typically self-limited 1
• Severe presentations include nephrotic-range proteinuria, acute kidney injury with elevated creatinine, and crescentic glomerulonephritis affecting up to 75% of glomeruli 3
• Long-term sequelae include persistent hypertension and end-stage kidney disease, though these are rare 1
• Pregnancy complications occur in women with childhood HSP history, including proteinuria and hypertension requiring close monitoring 2

Gastrointestinal Complications

Severe GI bleeding can occur and may require blood transfusions, with bleeding potentially originating from sites throughout the GI tract. 3

• Common manifestations include diffuse abdominal pain, gastritis, duodenitis, ileitis, and ulceration 3, 1
• Intussusception is a recognized complication requiring surgical evaluation 1
• Severe hemorrhage from the terminal ileum near Meckel's diverticulum has been reported, presenting with acute anemia (hemoglobin dropping to 3.5 g/dL) and positive fecal occult blood 3
• GI bleeding typically responds to symptomatic management and blood transfusions when severe 3

Cardiac Complications (Rare but Serious)

Cardiac involvement is exceptionally rare but carries a poor prognosis when present, requiring immediate recognition and treatment. 3, 4

• Arrhythmias including atrial fibrillation and non-sustained ventricular tachycardia can occur secondary to cardiac vasculitis 3
• Severe mitral regurgitation has been documented in children with HSP 4
• Treatment requires anti-arrhythmic drugs (metoprolol, amiodarone) and intensification of immunosuppressive therapy 3
• Cardiac involvement may be more common than previously recognized and indicates severe vasculitis 4

Pulmonary Complications (Rare but Life-Threatening)

Pulmonary hemorrhage is a rare complication that significantly increases morbidity and mortality and generally indicates severe vasculitis. 4

• Clinical significance: When present, pulmonary hemorrhage dramatically worsens prognosis 4
• Association: Often occurs in conjunction with other severe complications like cardiac involvement 4

Neurological Complications (Uncommon)

Neurological manifestations can develop weeks after initial presentation and require prompt recognition. 3

• Clinical findings include proximal muscle weakness, tremors, and upper and lower extremity clonus 3
• Timing: May present 7 weeks or more after initial treatment 3
• Management: Requires intensification of immunosuppressive therapy with agents like cyclophosphamide 3

Musculoskeletal Complications

Arthritis or arthralgia affects multiple joints and is part of the diagnostic criteria. 1, 5

• Presentation: Joint pain and swelling, particularly in lower extremities 3, 1
• Course: Typically self-limited and resolves without long-term sequelae 1

Clinical Monitoring Algorithm

All children with HSP require follow-up for at least 6 months with specific surveillance parameters. 2

• Regular urine testing for proteinuria and hematuria at each visit 2
• Blood pressure measurement at every follow-up to detect hypertension 2
• Renal function monitoring with BUN and creatinine when nephritis is present 3
• Cardiac evaluation with EKG and telemetry if palpitations, syncope, or dizziness develop 3
• Immediate evaluation for acute anemia, severe abdominal pain, or neurological symptoms 3

Important Caveats

Adolescents may experience more severe presentations compared to younger children and require closer monitoring for all complications. 3

The average disease duration is 4 weeks, but complications can develop at any point during or after the acute illness, necessitating prolonged surveillance. 1

Early steroid treatment does not reduce the incidence or severity of nephropathy, though corticosteroids may be beneficial for severe GI pain and hemorrhage. 1