Henoch-Schonlein purpura is a leucocytoclastic systemic vasculitis involving small vessels with the deposition of immune complexes containing IgA. It is characterized by the association of skin, joint and gastrointestinal manifestations. Even though the evolution is usually simple, some patients, especially adults, may have severe visceral involvement including heart, lung, brain and renal disease. The best treatment is currently unknown. This study will test the safety and efficacy of steroids associated or not with cyclosphosphamide to treat the acute lesions and to prevent the development of chronic lesions.

The protocol test the role of 2 modalities of treatment (steroid vs. steroid and cyclophosphamide) for severe systemic form of Henoch-Schonlein purpura. The severe forms include extracapillary glomerulonephritis, myocarditis, pneumonitis, occult involvement, severe gastro-intestinal bleeding. No other randomized trial has been performed in adult patient for this indication.

Inclusion Criteria:

• Patients with Henoch-Schoenlein purpura
• Patient's age > 18 years

Exclusion criteria:

• Patient presenting a purpura RHEUMATOID the diagnosis of which is confirmed by the histology presenting at least a visceral infringement(achievement) making consider the affection as engraves(burns)
• of 18 or more years old Patient
• Patient capable of understanding(including) the advantages and the risks of the try
• Patient having given his assent lit in writing