Henoch–Schönlein Purpura (HSP)

Henoch-Schönlein Purpura (HSP) is a common pediatric IgA vasculitis characterized by widespread IgA deposition in blood vessel walls, typically affecting children aged four to six. The clinical presentation centers on a hallmark palpable purpura rash appearing symmetrically below the beltline, often accompanied by colicky abdominal pain, arthritis in the knees and ankles, and localized angioedema. While most cases are self-limited and managed supportively with over-the-counter analgesics, nephritis remains the most serious complication, requiring diligent monitoring of blood pressure and urinalysis for weeks following diagnosis. Rare but severe manifestations include ileoileal intussusception and scrotal swelling. Diagnosis is primarily clinical, though ultrasound is indicated for suspected intussusception or testicular torsion. Outpatient management is appropriate for well-appearing children who can ambulate and show no signs of renal distress, provided they have close primary care follow-up to monitor for recurrence or chronic kidney disease.