Henoch-Schönlein Purpura

Most common childhood systemic vasculitis; rare in adults.

Reported annual incidence varies between 10-30 cases per 100,000 in children younger than 17 y and 3.4–14.3 cases per million in adults.

Mean age of presentation is 6 y; mainly affects children between 4-11 y of age in up to 90% of cases.

Occurs most commonly in spring; associated with recent URTIs in 90% of cases.

Cases are reported all over the world; highest incidence is found in Caucasians and lowest in African Americans in North America.

Morbidity/periop complications increase with abnormal renal function and neurologic/pulm/cardiovascular involvement/emergency surgery.

Problems of concurrent supportive medications (NSAIDs, immunosuppressants, steroids, ACE inhibitors) that the pt may be taking

Hypoproteinemia due to proteinuria if renal involvement

Anemia due to hematuria if renal involvement and GI bleeding

Fluid and lyte imbalance due to N/V and renal involvement

HSP is an acute, self-limiting, autoimmune, small vessel childhood vasculitis commonly affecting those of the dermis, bowel wall, and rarely the ureter, myocardium, adrenals, brain, and lungs. Glomerular mesangial hypercellularity with endocapillary proliferation occurs commonly.

It begins commonly with a nonthrombocytopenic purpuric rash. Arthritis or arthralgia is present in three-quarters of children and approximately 61% adults. GI symptoms occur in up to 85% of children and 48% of adults. Renal involvement is seen in 20–55% of children and approximately 32% of adults. GN is seen in a third of cases and may manifest as isolated hematuria, hypertension, or nephritic/nephrotic syndrome. 1–5% of children and 50% of adults with renal involvement progress to ESRD. Renal failure is the most common cause of death. The disease usually runs its entire course in 4 wk, and many children have no permanent sequelae. Renal symptoms can develop up to 3 mo after initial presentation. The course is complicated in adults.

HSP is a clinical Dx, and none of the laboratory features are pathognomonic. Palpable purpura plus at least one feature like diffuse abdominal pain/IgA deposition in any biopsy/arthritis/renal involvement suggests the Dx.