Psoriasis: an overview

Psoriasis is defined as a systemic, immune-mediated inflammatory skin disease, which typically follows a chronic relapsing course (National Institute for Health and Care Excellence (NICE), 2017). The long-term nature of the condition can be very distressing for affected patients, impacting on quality of life. Psoriasis can develop at any age, affecting males and females equally, but is rare in children, and most cases present before the age of 35 years (Knott, 2021). There are several types of psoriasis, which can affect different sites of the body. Of these, chronic plaque psoriasis is the most common form, accounting for 80–90% of cases (Knott, 2021). Other types are shown in Table 1.

Source: McKechnie, 2023; NICE, 2023

Chronic plaque psoriasis, the most common variant, typically presents with well-demarcated circular to oval bright red/pink lesions (plaques) with an overlying white or silvery scale (Knott, 2021). Lesions often have a paler outer edge. The most frequent symptoms experienced are, according to the World Health Organization (2016):