A Safety Study of Ustekinumab in the Treatment of Pediatric Participants Aged 6 Years and Older With Moderate to Severe Plaque Psoriasis

Inclusion Criteria: * Have a confirmed diagnosis of moderate to severe chronic plaque psoriasis * Either start therapy with ustekinumab for the treatment of psoriasis within 2 months after the first assessment in the study or have started therapy with ustekinumab in the 12-week period before the first assessment in the study; a. the treatment decision must have been taken independently of and prior to a participant's inclusion in the study; b. where participants have started therapy with ustekinumab before the first assessment in the study, appropriate baseline data at the start of ustekinumab treatment must be documented, including psoriasis area and severity index (PASI), physician global assessment of disease (PGA), body surface area (BSA) and children's dermatology life quality index (CDLQI) scores where available * Participants (and/or a legally-acceptable representative/guardian where applicable) must sign a participation agreement/informed consent form (ICF) allowing source data collection and verification in accordance with local requirements and the participants (and/or a legally-acceptable representative/guardian where applicable) must be able to understand and complete the requested patient-reported outcomes (PROs) * Be willing to participate in the study Exclusion Criteria: * Is enrolled in an interventional clinical study