Suspected SpA patients showed longer disease duration, increased NSAID use and higher prevalence of enthesitis, psoriasis and peripheral arthritis compared to non-SpA patients.<h4>Conclusions</h4>This study confirms the strong associations of HLA-B*51 with Behçet's disease and HLA-B*27 with spondyloarthritis while revealing additional heterozygous and less common alleles that suggest a broader genetic influence. The gene discussed is HLA-B; the disease is psoriasis.