Regarding which risk factors for progression from psoriasis to PsA should be considered, obesity, the presence of arthralgia, severe psoriasis, a history of uveitis, nail psoriasis, scalp psoriasis and having a first-degree relative with PsA reached consensus in round 1 of the Delphi exercise (median >70 mm on a 100-mm VAS), whereas any associated gene (such as HLA-B*08, HLA-B*27, HLA-B*38 or HLA-B*39) reached consensus in round 2 of the Delphi exercise (Supplementary Figure 1). Here, HLA-B is linked to psoriasis.