Psoriasis is an inflammatory skin disease that can be associated with joint inflammation (arthritis). Childhood psoriasis is frequently more severe when compared to adult-onset disease. Studies in adults suggest that psoriasis is caused by activated immune cells that cause damage. However, disease mechanisms, treatment response and outcomes are largely unstudied in children. The involvement of immune cells in psoriasis has been established. Determining types and numbers of immune cells may allow early diagnosis and the prediction of the development of arthritis. Patterns identified in this study may allow a personalized approach to treatment. Using modern single cell imaging technology, this study aims to investigate immune cells in controls and patients to understand disease mechanisms and deliver markers of individual outcomes, such as the development of arthritis. Understanding the composition and characteristics of immune cells in psoriasis will result in predictors of disease outcomes and new individualised treatments.