Pediatrics
A child previously diagnosed with HSP presents with new-onset abdominal pain, bilateral ankle swelling, and…
A child previously diagnosed with HSP presents with new-onset abdominal pain, bilateral ankle swelling, and hematuria with proteinuria on urinalysis. There is also a family history of SLE. What is the most likely cause of his current presentation?
Explanation
Core Concept: Henoch-Schönlein Purpura (HSP) / IgA Vasculitis. The most common systemic vasculitis in children, characterized by IgA immune complex deposition in small vessels. It classically affects the skin, joints, gastrointestinal tract, and kidneys.
Clinical Presentation:
- Palpable purpura (typically on buttocks and lower extremities).
- Migratory polyarthritis/arthralgia, colicky abdominal pain (risk of intussusception), and renal involvement (hematuria, proteinuria).
Diagnosis:
- First-line: Clinical diagnosis based on the classic tetrad of symptoms in a child following a URI.
- Gold Standard: Skin or renal biopsy showing leukocytoclastic vasculitis with IgA deposition on immunofluorescence (rarely needed in classic pediatric presentations).
Management:
- Acute: Supportive care with hydration and NSAIDs for joint pain. Monitor blood pressure and urinalysis closely. Systemic corticosteroids may be used for severe GI pain.
- Definitive: Most cases are self-limiting and resolve within weeks. Long-term follow-up is essential to monitor for the development of chronic IgA nephropathy or hypertension.