hsp virus

In medicine (rheumatology and pediatrics) Henoch-Schönlein purpura (HSP, also known as allergic purpura) is a systemic vasculitis characterized by prominent tissue deposition of IgA-containing immune complexes, especially in the skin and kidney. It has a prominent cutaneous involvement similarly seen in mixed cryoglobulinemia and hypersensitivity vasculitis: palpable petechiae or purpura is a major finding in these disorders. The pathogenesis is similar to that of IgA nephropathy, with similar histologic findings in the kidney.

Epidemiology

HSP occurs more often in children than in adults, and usually follows an upper respiratory tract infection. Half of affected children are below the age of five. Whitehead Institute - Vaccine Technology Homes in on Cancer. When adults are affected, the disease progression is more severe, with more renal involvement, and requiring more aggressive treatment, including corticosteroids and cytotoxic therapy. The incidence of HSP is about 1:7,000 in the United States. The median age is 6 years at disease onset, and 90% is under 10 years old. Boys tend to be more often affected than girls.

Signs and symptoms

The symptoms of HSP are usually preceded by a viral upper respiratory tract infection. encephalitis (brain inflammation) from a virus. The classic tetrad of HSP --- which can occur in any order at any time --- are, in order to decreasing frequency: