Ankylosing spondylitis patients with and without psoriasis do not differ in disease phenotype. Issue 6 (19th February 2013) - Machado, Pedro; Landewé, Robert; Braun, Jürgen; Baraliakos, Xenofon; Hermann, Kay-Geert A; Hsu, Benjamin; Baker, Daniel; van der Heijde, Désirée