Inclusion Criteria:  Diagnosis of Psoriasis by a dermatologist Aged 18 or more Reasonable fluency of spoken English  Exclusion Criteria:  Existing diagnosis of Psoriatic arthritis Currently on biologics for treatment of their skin Psoriasis (as this would potentially treat and thereby diminish joint symptoms associated with PsA) Aged <18years old (the study focusses on an adult population) Currently in prison (would be unable to attend the study ultrasound scan) Unable to give written consent for a musculoskeletal ultrasound e.g. advanced dementia, learning difficulties (may be unable to appreciate the reason for the study and may be unable to tolerate sitting relatively still for an ultrasound scan for 60 minutes)