In this chapter, the clinical characteristics of Henoch-Schönlein purpura (HSP), the most common systemic vasculitis of small-sized blood vessels in school-aged children, are described. The diagnosis is easier in the presence of the typical skin lesions, petechiae, palpable purpura and ecchymoses that predominantly involve the lower extremities and buttocks and rarely the upper extremities, face and trunk. Subcutaneous oedema over the dorsum of hands, feet, forehead and around the eyes may be also observed. Skin lesions appear on crops and may often recur. In several cases, abdominal pain, gastrointestinal bleeding, haematemesis and melena may be the first manifestations of the disease and in two-third of children represent the most severe complications. Vasculitis of the bowel may provoke intussusceptions and gut perforation. One-third of children will have glomerulonephritis but only 10 % nephritic or nephrotic syndrome, hypertension or renal failure. Isolated microhaematuria and/or proteinuria is common within the first 4–6 weeks and can continue for months though urinalysis generally normalizes in a few weeks. No specific blood tests are available for the HSP, and urinalysis may be the only abnormal exam. HSP is a benign self-limiting condition that lasts 2–4 weeks; only one-third of patients may have a recurrent disease which usually subsides within 3–6 months. Longer course has been reported in patients with renal involvement. Only 1–3 % of cases reach end-stage renal disease. There is no specific treatment of HSP. No significant benefit of short-course prednisone given at HSP onset has proved to be helpful in preventing persistent renal disease. According to PRES/EULAR criteria, at least one of the following may be present in addition to palpable purpura: diffuse abdominal pain, any biopsy showing predominant IgA deposition, arthritis or arthralgia and renal involvement (any haematuria and/or proteinuria).
KeywordsNephrotic Syndrome Renal Involvement Proliferative Glomerulonephritis Leukocytoclastic Vasculitis Postcapillary Venule