The purpose of this study is to assess the impact of adding two questions and pictures to the validated PEST on the potential diagnosis of PsA in participants with moderate-to-severe plaque PsO in Canada.

Patients will be enrolled in the study for up to 120 days and will be asked to fill-out a PsA screening questionnaire at their first dermatologist visit. Patients screening positive for PsA will have a second visit with a rheumatologist where a full PsA diagnosis assessment will be performed. A remote 'end of study' (EOS) visit will be conducted by the dermatologist to document the patient's biologic Disease-Modifying Antirheumatic Drugs (bDMARDs) treatment choice and status.

Key inclusion criteria:

1. Moderate-to-severe plaque PsO patients who are candidates for bDMARDs, according to physician's clinical judgement at the time of patient enrollment.
2. Adult patients at the time of informed consent signature
3. Patients able to understand and willing to comply with protocol requirements, instructions, and restrictions
4. Residents of Canada

Key exclusion criteria:

1. Patients who have previously screened positive for PsA through PEST.
2. Patients who have been diagnosed with PsA.
3. Patients who have been diagnosed with inflammatory arthritis unrelated to PsA (rheumatoid arthritis, reactive arthritis, enteropathic arthritis, axial spondyloarthritis)
4. Patients treated with a bDMARD for moderate-to-severe plaque PsO or any other medical condition within the last 6 months prior to patient enrollment.

Novartis is committed to sharing access to patient-level data and supporting clinical documents from eligible studies with qualified external researchers. Requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to protect the privacy of patients who have participated in the trial in line with applicable laws and regulations.