What is the description of psoriasis skin?

From the Guidelines

Psoriasis skin is characterized by well-demarcated, red plaques with silvery scale, commonly involving the scalp, elbows, knees, and presacral region, though any area of skin may be involved. The affected skin is often itchy, painful, and may crack or bleed. In some cases, the skin around joints can become so inflamed that movement becomes difficult. Psoriasis plaques result from an accelerated skin cell production process where new cells develop too quickly and accumulate on the surface instead of shedding normally. This autoimmune condition varies in severity from a few small spots to large areas covering significant portions of the body. The appearance can change with flare-ups and remissions, sometimes becoming more inflamed during stress, illness, or certain weather conditions. The distinctive silvery scale is a hallmark feature that helps distinguish psoriasis from other skin conditions like eczema. Some key features of psoriasis skin include:

• Red, inflamed patches covered with thick, silvery-white scales
• Plaques typically appear on the elbows, knees, scalp, and lower back
• Affected skin is often itchy, painful, and may crack or bleed
• Skin around joints can become inflamed, making movement difficult
• Severity varies from mild to severe, with some cases having significant emotional consequences or impacting daily life 1. The Psoriasis Area Severity Index (PASI) is a tool used to quantify the extent and severity of psoriasis, taking into account the intensity of redness, scaling, and plaque thickness, but it is rarely used in clinical practice 1. Overall, psoriasis is a chronic inflammatory skin disease that requires proper management and treatment to alleviate symptoms and improve quality of life, with the most recent guidelines recommending a comprehensive approach to care 1.

From the FDA Drug Label

The sPGA is a 6-category scale ranging from "5 = severe" to "0 = none" indicating the physician's overall assessment of the PsO severity focusing on induration, erythema and scaling. Treatment success of "clear" or "minimal" consisted of none or minimal elevation in plaque, up to faint red coloration in erythema and none or minimal fine scale over < 5% of the plaque The individual components of the PASI (induration, erythema and scaling) contributed comparably to the overall treatment-associated improvement in PASI

The description of psoriasis skin includes:

• Induration (elevation in plaque)
• Erythema (red coloration)
• Scaling (fine scale over the plaque) These components are used to assess the severity of psoriasis using the Psoriasis Area and Severity Index (PASI) and the Static Physician Global Assessment (sPGA) 2

From the Research

Description of Psoriasis Skin

• Psoriasis is a recurring inflammatory skin condition characterized by scaly, red patches on the skin 3
• The skin condition is associated with histological changes such as epidermal hyperplasia, increased blood vessel proliferation, and infiltration of leukocytes into the skin's dermis 3
• Psoriatic plaques are defined by epidermal hyperplasia, epidermal and dermal infiltration by leukocytes, and changes in the dermal microvasculature 4
• The plaques are typically elevated, red, and scaly, and can appear on specific body sites such as the extensor sites of the extremities 5

Characteristics of Psoriatic Lesions

• Differentiation and activation are disturbed in lesional psoriatic keratinocytes, and the pool of proliferating keratinocytes is increased 4
• There is enhanced production of proinflammatory cytokines, adhesion molecules, and antimicrobial peptides in psoriatic keratinocytes 4
• The number of T cells, and myeloid and plasmacytoid dendritic cells (DCs) is markedly increased in psoriatic lesions 4
• Myeloid DCs produce interleukin (IL)-23, tumour necrosis factor (TNF)-alpha, and inducible nitric oxide synthase (iNOS), which are crucial cytokines in the pathogenesis of psoriasis 4

Clinical Presentation

• Psoriasis is a chronic inflammatory skin disease induced by multifactorial causes and is characterized by bothersome, scaly reddish plaques 5
• The disease can affect approximately 3% of the US population and is associated with a significant impact on quality of life 3
• Psoriasis can be accompanied by arthritis that can affect any joint, the spine, and/or include enthesitis 6