Dose Reduction of IL17 and IL23 Inhibitors in Psoriasis

Inclusion Criteria: * Plaque psoriasis (primarily) * Treatment for at least 6 months with IL23 or IL17 inhibitor in a normal dose (dose advised by the label) * PASI≤ 5 at inclusion and in previous 6 months (if no PASI scores are available, it should be clear from the patient record that psoriasis was clear/almost clear in previous 6 months). * DLQI ≤ 5 at inclusion Exclusion Criteria: * Another indication than plaque psoriasis as the main indication for biologic use (e.g. patient receives biologic for rheumatoid arthritis as the main indication). * Concomitant use of systemic immunosuppressants other than methotrexate or acitretin (e.g. prednisone, cyclosporine etc). * Severe comorbidities with short life-expectancy (e.g. metastasized tumor). * Presumed inability to follow the study protocol.