What is psoriasis?

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Last updated: May 28, 2025View editorial policy

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From the Guidelines

Psoriasis is a chronic inflammatory disease affecting approximately 2% of the population, characterized by patches of red, inflamed skin covered with thick, silvery scales, and is associated with considerable morbidity and comorbid conditions 1. The condition occurs when skin cells multiply too quickly, causing cells to build up on the skin's surface, and is believed to be caused by a combination of genetic predisposition and environmental triggers such as stress, infections, injuries to the skin, and certain medications.

Key Characteristics of Psoriasis

  • Approximately 80% of patients with psoriasis have mild to moderate disease, whereas 20% have moderate to severe disease 1
  • The severity of psoriasis is defined not only by extent of body surface area (BSA) involvement, but also by involvement of the hands, feet, facial, or genital regions 1
  • Psoriasis is associated with an increased incidence of lymphoma, heart disease, obesity, type 2 diabetes, and the metabolic syndrome 1

Treatment Options

  • Topical corticosteroids like betamethasone or clobetasol for mild cases, applied once or twice daily to affected areas
  • Phototherapy, oral medications like methotrexate or cyclosporine, or biologic injections such as adalimumab (Humira) or secukinumab (Cosentyx) for moderate to severe cases 1
  • Maintaining a healthy lifestyle with stress management, regular moisturizing, avoiding skin injuries, and limiting alcohol can help reduce flare frequency and severity The goal of treatment is to reduce symptoms, improve quality of life, and minimize the risk of comorbid conditions, with a focus on individualized care and ongoing management 1.

From the FDA Drug Label

The safety and efficacy of Enbrel were assessed in two randomized, double-blind, placebo-controlled studies in adults with chronic stable PsO involving ≥ 10% of the body surface area, a minimum Psoriasis Area and Severity Index (PASI) score of 10 and who had received or were candidates for systemic antipsoriatic therapy or phototherapy Patients with guttate, erythrodermic, or pustular psoriasis and patients with severe infections within 4 weeks of screening were excluded from study.

Psoriasis is a chronic skin condition characterized by inflammation and skin lesions, with various forms including plaque, guttate, erythrodermic, and pustular psoriasis. Key features of psoriasis include:

  • Induration (thickening of the skin)
  • Erythema (redness of the skin)
  • Scaling (flaking of the skin) The Psoriasis Area and Severity Index (PASI) is a composite score used to assess the severity of psoriasis, taking into account the fraction of body surface area affected and the nature and severity of psoriatic changes within the affected regions 2.

From the Research

Definition of Psoriasis

  • Psoriasis is an inflammatory skin condition that affects approximately 2% of people worldwide 3.
  • It is a chronic, recurring inflammatory disease affecting the skin, joints, and nails, with a significant negative impact on the quality of life 4.
  • Psoriasis is associated with multiple comorbidities, including psoriatic arthritis, cardiometabolic diseases, and depression, and substantially diminishes patients' quality of life 5.

Types of Psoriasis

  • Plaque psoriasis is the most common variant of psoriasis 5.
  • Other types of psoriasis are not specified in the provided studies, but plaque psoriasis is the focus of most treatments and research.

Treatment Options

  • Topical treatments, systemic treatments, biologic agents, and phototherapy are all treatment options for psoriasis 3.
  • Topical corticosteroids remain the most commonly prescribed agents for psoriasis, but they are frequently prescribed with other agents 6.
  • Biologics, such as inhibitors to tumor necrosis factor α (TNF-α), are an option for first-line treatment of moderate to severe plaque psoriasis 5.
  • Narrowband UV-B phototherapy is a commonly used treatment for psoriasis, especially for patients with extensive plaque-type psoriasis 7, 4.
  • Combination of methotrexate and narrowband UV-B phototherapy provides more rapid clinical improvement compared with narrowband UV-B monotherapy in the treatment for chronic plaque-type psoriasis 4.

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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