Psoriatic arthritis is a condition that can develop in people with psoriasis, causing joint pain, stiffness, swelling, and inflammation. However, it may not appear suddenly. In many patients, the disease may develop gradually through earlier stages, when symptoms are already present but arthritis has not yet been formally diagnosed. The SPADE study looked at 122 people with psoriasis who later developed psoriatic arthritis. The aim was to understand whether simple clinical signs present before diagnosis could help identify patients at risk of more severe disease or earlier progression. Many patients already had musculoskeletal symptoms at their first rheumatological evaluation, and in more than one third of cases these symptoms were considered inflammatory by the rheumatologist. This suggests that some patients may already be in an “at-risk” phase before psoriatic arthritis becomes clinically clear. We found that morning stiffness and higher levels of C-reactive protein, a blood marker of inflammation, were associated with more active psoriatic arthritis at diagnosis. Female sex and morning stiffness also seemed to be linked to a more aggressive disease presentation. Interestingly, higher C-reactive protein was associated with more active disease at diagnosis, but also with greater improvement during the first year of follow-up. This may be because patients with clearer signs of inflammation receive earlier or more intensive treatment. We did not identify strong predictors of faster transition from psoriasis to psoriatic arthritis. Overall, patients with psoriasis, musculoskeletal symptoms, persistent morning stiffness, or raised inflammatory markers may benefit from earlier rheumatology referral.