1. Allez M, Lemann M, Bonnet J, Cattan P, Jian R, Modigliani R (2002) Long term outcome of patients with active Crohn’s disease exhibiting extensive and deep ulcerations at colonoscopy. Am J Gastroenterol. 97(4):947–953
2. Baumgart D, Phillip S (2018) Kapitel 17. Hautmanifestationen und sekundäre Manifestationen. In: Kucharzik T, Rijcken E, Bettenworth D, Senninger N (Hrsg) Therapie chronisch entzündlicher Darmerkrankungen, 1. Aufl. de Gruyter, Berlin
3. Baumgart DC, Sandborn WJ (2012) Crohn’s disease. Lancet 380(9853):1590–1605
4. Beaugerie L, Massot N, Carbonnel F, Cattan S, Gendre JP, Cosnes J (2001) Impact of cessation of smoking on the course of ulcerative colitis. Am J Gastroenterol. 96(7):2113–2116
5. Beaugerie L, Seksik P, Nion-Larmurier I, Gendre JP, Cosnes J (2006) Predictors of Crohn’s disease. Gastroenterology. 130(3):650–656