The purpose of this study is to evaluate the long-term course of patients with psoriasis and psoriatic-arthritis in systemic treatments such as, methotrexate, cyclosporin A, fumaric acids, acitretin, systemic PUVA, etanercept, infliximab, adalimumab and ustekinumab. A patient will be included at first initiation of the treatment and will remain in the registry for 10 years, regardless of subsequent therapy.

The registry will also evaluate safety clinical outcomes and health related quality of life.

Treatment of moderate to severe Psoriasis (Pso) and Psoriasis-Arthritis (PsA) in Switzerland is largely performed with systemic therapies. This includes conventional systemic therapy such as fumaric acids, methotrexate, cyclosporin A, retinoids, systemic PUVA, Acitretin and biological treatments such as etanercept, infliximab, adalimumab and within a pre-registration program ustekinumab. While short- and middle-term efficacy of most systemic treatments has been shown in clinical studies (and is incorporated in international guidelines), knowledge about long-term outcomes, optimal treatment and effectiveness under real-world conditions is still missing. SDNTT, the Swiss registry on the treatment of moderate to severe Pso and PsA documents the long-term course of patients being administered a defined biologic or conventional systemic drug. Following outcomes are observed: Effectiveness on the long-term, of combined/alternating treatments and under comorbidity conditions; patient-defined benefits and quality of life, maintenance dosages, prediction of response and safety.

The study evaluates the long-term course of patients with Pso and PsA in systemic treatments. A patient will be included at first initiation of the treatment and will remain in the registry for 5 years, regardless of subsequent therapy. Nationwide, initially 35 (long-term approx. 50-80) dermatologic practices and hospital ambulances with expertise in systemic and biologic treatment will consecutively enroll patients. Follow-ups will be every 3 months, comprising patient and treatment characteristics, clinical parameters, patient-defined benefit, quality of life and adverse events. Standardized questionnaires will be addressed to the patient and to the dermatologist 12 times at the dermatologic centres. In interim intervals, patients are directly contacted another 9 times by mail.

Inclusion Criteria:

• Patients with diagnosis of plaque-type psoriasis or psoriasis arthritis confirmed by a dermatologist,
• age ≥ 18,
• Being administered a specific biologic/conventional systemic drug for the first time
• Sufficient language skills (German, French, Italian and English) for the informed consent to participate
• Informed consent to participate

Exclusion Criteria:

• Lack of informed consent
• Patients being participants of clinical trials at the day of registration to the registry (if a patient is included into a clinical trial during the registry follow-ups, the patient data will be recorded, but analyzed separately)

Any patient with psoriasis or psoriatic-arthritis meeting the inclusion criteria and not meeting the exclusion criteria will be eligible to participate in this registry.