Psoriatic arthritis (PsA) is a chronic, autoimmune inflammatory condition that can affect up to 30% of patients with psoriasis. It is part of the seronegative spondyloarthropathy group of rheumatic diseases which also includes reactive arthritis and ankylosing spondylitis. It can be a multisystem disease affecting the eyes, the gut and the tendons and is associated with comorbidities such as ischaemic heart disease and metabolic syndrome. Early diagnosis is key as structural joint damage can occur within two years of disease onset.