See: [RCH HSP](https://www.rch.org.au/clinicalguide/guideline_index/HenochSchonlein_Purpura/), [HSP -- Rosens](x-devonthink-item://000D12F3-1F5B-4BD9-A664-3C375B107DE5?page=12) see also: [[glomerulonephritis|post-strep glomerulonephritis]] Immunologically-mediated vasculitis > [!key points] > HSP is commonly associated with abdominal pain, palpable purpuic rash, arthralgias, and renal disease. Its incidence is highest among children 4 to 11 years of age. It more commonly occurs during the spring season following viral upper respiratory infections. > > *Clinical Features* > Patients are usually diagnosed clinically on the basis of the classic ==palpable purpuric rash located on the buttocks and lower extremities==. Up to **70% of patients have GI complaints**, including *abdominal pain*, nausea and vomiting, diarrhea, **intestinal bleeding**, and ileoilel [[Intussusception]]. > > Laboratory findings are signicant for a ==lack of thrombocytopenia==. (don't confuse with *HUS*, which also has renal issues). **Microscopic hematuria** occurs in half of patients. The syndrome is often relapsing and remitting for several weeks and may be associated with arthralgias. Neurologic involvement is uncommon # features - **Abdo pain, GI bleeding** - can get colicky pain, bloody diarrhoea, and [[Intussusception]] - **palpable purpura** = vasculitis - migratory, large-joint arthritis - *renal involvement*: haematuria, proteinuria - often preceding upper resp infection > **dx:** > Palpable purpura in a person with normal platelet count and normal coagulation who has one or more of the following:  > 1. Diffuse **abdominal pain** > 2. Histopathology: typical LCV with predominant **IgA deposits** or proliferative [[glomerulonephritis]] with predominant IgA deposits  > 3. **Arthritis** or arthralgias > 4. **Renal involvement** (proteinuria: >0.3 g 24 h or >30 mg mmol of urine albumin to creatinine ratio on a spot morning sample; and/or haematuria, red blood cell casts: ≥5 red cells per high power field or ≥2+ on dipstick or red blood cell casts in the urinary sediment). # demographics - 2-11, whites, winter, males # diagnosis - **skin lesions are pathognomonic**: round, palpable, symmetrical, on dependent areas of legs and buttocks, extensor surfaces - ==normal platelets, PT, and aPTT== - urinalysis indicated - if HTN, proteinurea, or macroscopy haematuria, do urinary protein-Cr ratio, UEC, albumin ![[Pasted image 20230823013256.png]] # Treatments - 4-6 weeks of illness - give *steroids* if symptomatic ![[Pasted image 20230823013408.png]]