Psoriasis presents as well-defined erythematous plaques covered with silvery scales, commonly over the scalp and extensor surfaces of the extremity. It may be itchy but is less common and severe than with atopic dermatitis (eczema). The lesions of psoriasis are distinct from other entities and are classically very well circumscribed, circular, red papules or plaques with a grey or silvery-white, dry scale. In addition, the lesions are typically distributed symmetrically on the body.Source: Update on psoriasis: A review – PMC (opens in a new tab)
There are various forms of psoriasis which include plaque psoriasis, pustular psoriasis, erythrodermic psoriasis, guttate psoriasis and inverse psoriasis. It is beyond the scope of this patient context information to discuss these individually, but more information can be found in the source below if of specific interest. Plaque psoriasis is the most common and accounts for 80–90% of all cases.Sources: A brief summary of clinical types of psoriasis – PMC (opens in a new tab); Plaque Psoriasis – StatPearls – NCBI Bookshelf (opens in a new tab)
The systemic nature of the disease means it can have a diverse set of clinical features with multisystem involvement. This includes the musculoskeletal system in a condition termed psoriatic arthritis. The disease can cause joint swelling and pain, commonly in the hands and feet along with tendon attachment sites (enthesis). Dactylitis is common and leads to localised, painful swelling of a finger or toe. Other common extra-articular sites include the nails; pitting (small, thimble-like dents); discolouration (yellow/brown ‘oil-drop’ spots); thickening, brittleness and onycholysis (separation from the nail bed) are common. Ocular features including uveitis (eye inflammation), inflammatory bowel disease (such as Crohn’s or colitis) and an elevated risk of cardiovascular and metabolic comorbidities can also occur.Sources: Psoriatic Arthritis – StatPearls – NCBI Bookshelf (opens in a new tab); Nail Psoriasis – PubMed (opens in a new tab); The Risk of Systemic Diseases in Those with Psoriasis and Psoriatic Arthritis: From Mechanisms to Clinic – PMC (opens in a new tab)
