Henoch-Scholein Purpura Flashcards
How important, epidemiologicaly, is HSP?
Henoch–Schönlein purpura (HSP) is the most common vasculitis of childhood.
How common is HSP?
HSP can affect all age groups but most commonly children between 2 and 6 years of age. The incidence in children is reported as between 10.5 and 20.4/100,000 children per year.
How is HSP diagnosed?
Palpable purpura (essential) in the presence of one of the following:
- Diffuse abdominal pain
- Any biopsy showing predominant IgA
- Acute arthritis/arthralgia
- Renal involvement defined as any haematuria or proteinuria.
What is the pathophygiology of HSP?
The pathogenesis of HSP is not yet clearly understood, although it is known to be an immune complex-mediated
disease. IgA complexes are formed and deposited in the skin, gut and glomeruli triggering a localised inflammatory response. A leucocytoclastic vasculitis subsequently develops with necrosis of the small blood vessels.
Preceding upper respiratory tract infections are common particularly with group A β-haemolytic streptococcus,but many other organisms have been implicated such as mycoplasma, adenovirus, parvovirus B19, varicella and herpes simplex.
What are the microscopic findings of HSP with kidney involvement?
In the skin, a biopsy of the purpura (but also of the nonaffected areas) reveals IgA deposition. In the kidney, the histological findings are similar to that of IgA nephropathy. Primarily, there is mesangial proliferation with hypercellularity. There may be focal necrosis and segmental capillary collapse.
How to manage a patient with HSP?
The natural course of the disease is usually one of complete resolution, often without the need for therapeutic intervention.
Patients often require admission to hospital, particularly for symptom control.
There remains uncertainty regarding optimal monitoring and therapy. Nonrenal involvement is common, and there may be a role for steroids in treating GI involvement. There is, however, no evidence that early steroids reduce the risk of developing renal complications. Renal involvement can be severe but may resolve completely. However, some children will develop long-term sequelae, and renal biopsy is helpful in determining the need for treatment with immunosuppression in the acute phase.
