1. Henoch-Scholein Purpura

2. Introduction Systemic vasculitis with a prominent cutaneous component. Systemic vasculitis with a prominent cutaneous component. Skin vasculitis with palpable petechiae or purpura is typically a major finding. Skin vasculitis with palpable petechiae or purpura is typically a major finding. Pathogenesis: tissue deposition of IgA- containing immune complexes, similar to IgA nephropathy. Pathogenesis: tissue deposition of IgA- containing immune complexes, similar to IgA nephropathy.

3. Clinical manifestations More often in children than in adults. More often in children than in adults. Half of affected children are under 5 y/o. Half of affected children are under 5 y/o. But adults had more severe and frequent renal involvement, and required more aggressive treatment. But adults had more severe and frequent renal involvement, and required more aggressive treatment. Many cases follow an URI, suggesting that the precipitating antigen may be infectious. Many cases follow an URI, suggesting that the precipitating antigen may be infectious.

4. Clinical manifestation Classic tetrad: relative frequency Classic tetrad: relative frequency Skin rash (purpura)100% Skin rash (purpura)100% Arthralgia82% Arthralgia82% Abdominal pain63% Abdominal pain63% Renal disease40% Renal disease40% GI bleeding33% GI bleeding33% CNS and lung may also involved. CNS and lung may also involved. Skin rash is typically purpuric and distributed symmetrically over the lower legs and arms. Skin rash is typically purpuric and distributed symmetrically over the lower legs and arms. Arthralgias most commonly affect the knees and ankles. Arthralgias most commonly affect the knees and ankles.

5. GI symptoms Colicky abdominal pain (due to local vasculitis) is frequently associated with vomiting. Colicky abdominal pain (due to local vasculitis) is frequently associated with vomiting. The pain typically develops within 8 days of appearance of the rash, but maybe longer. The pain typically develops within 8 days of appearance of the rash, but maybe longer. Bleeding is seen in up to 25% patients. Bleeding is seen in up to 25% patients. Rare complications: intussusception, pancreatitis, cholecystitis. Rare complications: intussusception, pancreatitis, cholecystitis.

6. Renal disease Hematuria and/or proteinuria, 30 - 70 % Hematuria and/or proteinuria, 30 - 70 % Microscopic hematuria with RBC casts. Microscopic hematuria with RBC casts. May progress to ESRD or chronic renal disese. related to cresent formation of glomeruli. May progress to ESRD or chronic renal disese. related to cresent formation of glomeruli.

7. Diagnosis D/D: clotting disorder, sepsis, hypersensitivity vasculitis, SLE D/D: clotting disorder, sepsis, hypersensitivity vasculitis, SLE Confirmation: tissue deposition in the skin or kidney of IgA by immunofluoresence microscopy. Confirmation: tissue deposition in the skin or kidney of IgA by immunofluoresence microscopy. Skin biopsy or renal biopsy. Skin biopsy or renal biopsy. HSP likely (more than 2 of below): palpable purpura, bowel angina, GI bleeding, hematuria, age<20 HSP likely (more than 2 of below): palpable purpura, bowel angina, GI bleeding, hematuria, age<20

8. Prognosis & Treatment Most of the patients recover completely spontaneously (> 90%). Most of the patients recover completely spontaneously (> 90%). Recurrences are common, occurring in approximately 1/3 of patients. Recurrences are common, occurring in approximately 1/3 of patients. Tx: steroid and immunosuppresant agent may be helpful but lack of strong evidence. Tx: steroid and immunosuppresant agent may be helpful but lack of strong evidence.