A Study of Guselkumab in Naive or Bio-experienced Participants With Regional (Facial and Genital) Psoriasis

Inclusion Criteria: Participants included in the study: * must have a first or confirmed diagnosis of psoriasis, requiring systemic treatment with significant involvement (defined as a Static Physician's Global Assessment \[sPGA\] score greater than or equal to \[\>=\] 3) involving the facial and/or genital regions * must have started treatment according to the approved indication as described in the current version of summary of product characteristics (SmPC) of the product approved in Italy. Enrollment may occur at any time after the first injection of guselkumab but before completion of the next visit at week 4 or 12 as scheduled according to common clinical practice * must sign an informed consent form (ICF) allowing data collection and source data verification in accordance with local requirements Exclusion Criteria: Participants will be excluded from the study if they: * have any contraindication to the use of guselkumab, as stated in the current SmPC of the product approved in Italy * received an investigational drug (including investigational vaccines) or used an invasive investigational medical device within 30 days before the start of guselkumab treatment * are currently enrolled in another clinical trial or investigational study * are currently enrolled in an observational study sponsored or managed by a Janssen company * participant unable to read, to write, to understand and sign the informed consent form (ICF)