J. Jennette, R. Falk, P. Bacon, N. Basu, M. Cid et al., 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides, revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides, pp.1-11, 2012.
DOI : 10.1097/BOR.0b013e3283412f7c

J. Gardner-medwin, P. Dolezalova, C. Cummins, and T. Southwood, Incidence of Henoch-Schonlein purpura, Kawasaki disease, and rare vasculitides in children of different ethnic origins, The Lancet, vol.360, issue.9341, pp.1197-202, 2002.
DOI : 10.1016/S0140-6736(02)11279-7

Y. Yang, C. Hung, C. Hsu, L. Wang, Y. Chuang et al., A nationwide survey on epidemiological characteristics of childhood Henoch???Scho??nlein purpura in Taiwan, Rheumatology, vol.44, issue.5, pp.618-640, 2005.
DOI : 10.1046/j.1365-2249.2000.01361.x

R. Watts, S. Lane, and D. Scott, What is known about the epidemiology of the vasculitides?, Best Practice & Research Clinical Rheumatology, vol.19, issue.2, pp.191-207, 2005.
DOI : 10.1016/j.berh.2004.11.006

M. Gonzalez-gay and C. Garcia-porrua, Systemic Vasculitis in Adults in Northwestern Spain, 1988-1997: Clinical and Epidemiologic Aspects, Medicine, vol.78, issue.5, pp.292-308, 1988.
DOI : 10.1097/00005792-199909000-00002
URL : http://pdfs.journals.lww.com/md-journal/1999/09000/Systemic_Vasculitis_in_Adults_in_Northwestern.2.pdf?token=method|ExpireAbsolute;source|Journals;ttl|1506160407034;payload|mY8D3u1TCCsNvP5E421JYK6N6XICDamxByyYpaNzk7FKjTaa1Yz22MivkHZqjGP4kdS2v0J76WGAnHACH69s21Csk0OpQi3YbjEMdSoz2UhVybFqQxA7lKwSUlA502zQZr96TQRwhVlocEp/sJ586aVbcBFlltKNKo+tbuMfL73hiPqJliudqs17cHeLcLbV/CqjlP3IO0jGHlHQtJWcICDdAyGJMnpi6RlbEJaRheGeh5z5uvqz3FLHgPKVXJzdDoKqmK31GBg+24iISnv/Sb2bmWnYbw77n+KaP5WGgvs=;hash|1SLspmHdDD10gtK+yQHrNw==

E. Pillebout and V. J. , Purpura rhumato??de de l???adulte, La Revue de M??decine Interne, vol.35, issue.6, pp.372-81, 2014.
DOI : 10.1016/j.revmed.2013.12.004

E. Pillebout, E. Thervet, G. Hill, C. Alberti, P. Vanhille et al., Henoch-Schonlein Purpura in Adults: Outcome and Prognostic Factors, Journal of the American Society of Nephrology, vol.13, issue.5, pp.1271-1279, 2002.
DOI : 10.1097/01.ASN.0000013883.99976.22
URL : http://jasn.asnjournals.org/content/13/5/1271.full.pdf

R. Coppo, G. Mazzucco, L. Cagnoli, A. Lupo, and F. Schena, Long-term prognosis of Henoch-Schonlein nephritis in adults and children, Nephrology Dialysis Transplantation, vol.12, issue.11, pp.2277-83, 1997.
DOI : 10.1093/ndt/12.11.2277

S. Shrestha, N. Sumingan, J. Tan, H. Alhous, L. Mcwilliam et al., Henoch Schonlein purpura with nephritis in adults: adverse prognostic indicators in a UK population, QJM, vol.99, issue.4, pp.253-65, 2006.
DOI : 10.1093/qjmed/hcl034

C. Garcia-porrua, C. Gonzalez-louzao, J. Llorca, and M. Gonzalez-gay, Predictive factors for renal sequelae in adults with Henoch-Schonlein purpura, J Rheumatol, vol.28, issue.5, pp.1019-1043, 2001.

E. Pillebout, C. Alberti, L. Guillevin, A. Ouslimani, and E. Thervet, Addition of cyclophosphamide to steroids provides no benefit compared with steroids alone in treating adult patients with severe Henoch Sch??nlein Purpura, Kidney International, vol.78, issue.5, pp.495-502, 2010.
DOI : 10.1038/ki.2010.150

A. Levey, J. Bosch, J. Lewis, T. Greene, N. Rogers et al., A More Accurate Method To Estimate Glomerular Filtration Rate from Serum Creatinine: A New Prediction Equation, Annals of Internal Medicine, vol.130, issue.6, pp.461-70, 1999.
DOI : 10.7326/0003-4819-130-6-199903160-00002

P. Austin, An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies, Multivariate Behavioral Research, vol.110, issue.3, pp.399-424, 2011.
DOI : 10.1016/j.drugalcdep.2009.03.018

B. Lee, J. Lessier, E. Stuart, R. Rosenbaum, and D. Rubin, Weight trimming and propensity score weighting The central role of the propensity score in observational studies for causal effects, Plos One. Biometrika, vol.370, issue.15, pp.41-55, 1982.

V. Calvo-rio, J. Loricera, C. Mata, L. Martin, F. Ortiz-sanjuan et al., Henoch-Sch??nlein Purpura in Northern Spain, Medicine, vol.93, issue.2, pp.106-119, 2014.
DOI : 10.1097/MD.0000000000000019

J. Wiley, &. Sons-arthritis, &. Rheumatology-17, S. Uppal, M. Hussain et al., Henoch-Schonlein's purpura in adults versus children/adolescents: A comparative study Henoch-Schonlein purpura in children and adults: clinical differences in a defined population, Clin Exp Rheumatol. Semin Arthritis Rheum, vol.2432, issue.183, pp.26-30149, 2002.

Y. Ilan, Y. Naparstek, S. Hung, Y. Yang, Y. Lin et al., Schonlein-Henoch syndrome in adults and children Clinical manifestations and outcomes of Henoch-Schonlein purpura: comparison between adults and children, Semin Arthritis Rheum. Pediatr Neonatol, vol.2150, issue.204, pp.103-9162, 1991.

A. Audemard-verger, E. Pillebout, L. Guillevin, E. Thervet, and B. Terrier, IgA vasculitis (Henoch???Sh??nlein purpura) in adults: Diagnostic and therapeutic aspects, Autoimmunity Reviews, vol.14, issue.7, pp.579-85, 2015.
DOI : 10.1016/j.autrev.2015.02.003

A. Huber, J. King, P. Mclaine, T. Klassen, and M. Pothos, A randomized, placebo-controlled trial of prednisone in early Henoch Sch??nlein Purpura [ISRCTN85109383], BMC Medicine, vol.136, issue.1, p.7, 2004.
DOI : 10.2214/ajr.136.6.1081

J. Ronkainen, O. Koskimies, M. Ala-houhala, M. Antikainen, J. Merenmies et al., Early prednisone therapy in Henoch-Sch??nlein purpura: A randomized, double-blind, placebo-controlled trial, The Journal of Pediatrics, vol.149, issue.2, pp.241-248, 2006.
DOI : 10.1016/j.jpeds.2006.03.024

O. Jauhola, J. Ronkainen, O. Koskimies, M. Ala-houhala, P. Arikoski et al., Clinical course of extrarenal symptoms in Henoch-Schonlein purpura: a 6- month prospective study Interventions for preventing and treating kidney disease in Henoch-Schonlein Purpura (HSP) The combination of mycophenolate mofetil with corticosteroids induces remission of Henoch- Schonlein purpura nephritis, CD005128. 26. Ren P, pp.871-6271, 2010.

R. Luqmani, P. Bacon, R. Moots, B. Janssen, A. Pall et al., Birmingham Vasculitis Activity Score (BVAS) in systemic necrotizing vasculitis, QJM, vol.87, issue.11, pp.671-679, 1994.

D. Cattran, J. Feehally, H. Cook, Z. Liu, F. Fervenza et al., Kidney disease: Improving global outcomes (KDIGO) glomerulonephritis work group. KDIGO clinical practice guideline for glomerulonephritis, Kidney International Supplements, vol.2, issue.2, pp.139-274, 2012.