Psoriasis.

Psoriasis is a chronic, immune-mediated inflammatory skin disease affecting 1.3-2.2% of the UK population.1 Most commonly, psoriasis is characterised by well-demarcated, red plaques with adherent scale with a predilection for the scalp and extensor surfaces of the limbs. However, the effects of psoriasis go far beyond a patient's skin and may result in a degree of disability and impaired quality of life similar to that of other major medical conditions, such as cancer and heart disease. First-line therapies for most patients are topical treatments such as topical corticosteroids and vitamin D analogues. For those with more severe or treatment-resistant disease, second- or third-line therapies include phototherapy, systemic therapies such as methotrexate and more recently biologic therapies such as tumour necrosis factor (TNF) inhibitors. These therapeutic modalities are proven to be highly effective; however, the potential for long-term toxicity needs to be considered. Aside from the visible skin disease, psoriasis is also increasingly recognised to have important systemic manifestations. Psoriatic arthritis has long been established as an associated condition and, more recently, it has emerged that psoriasis is also associated with an increased risk of inflammatory bowel disease, cardiovascular disease and the metabolic syndrome. Both National Institute for Health and Care Excellence (NICE)2 and Scottish Intercollegiate Guidelines Network (SIGN)3 have recently published guidelines for the assessment and management of psoriasis which highlight the need for regular assessment in order to detect the development of arthritis and the presence of other co-morbidities such as obesity, diabetes, dyslipidaemia and hypertension.