From the Guidelines
Psoriasis is a chronic autoimmune skin condition characterized by an interplay of genetic and environmental factors, leading to hyperproliferation of epidermal keratinocytes and a dysregulated immune response, with overactive T-cells, particularly the TH17 subset, playing a central role in its pathogenesis. The pathophysiology of psoriasis involves a complex interaction between the epidermis, dermis, cutaneous microvasculature, and immune system, resulting in scaling, thickened plaques, and erythema 1. Key points to consider include:
- Genetic and environmental factors contributing to the development of psoriasis
- Hyperproliferation of epidermal keratinocytes and dysregulated immune response
- Overactive T-cells, particularly the TH17 subset, playing a central role in pathogenesis
- Association with psoriatic arthritis, cardiovascular disease, metabolic syndrome, and other comorbidities
- Importance of early treatment to control symptoms, prevent structural damage, and improve quality of life
The clinical features of psoriasis include well-demarcated, erythematous plaques with silvery scales, and the Auspitz sign (pinpoint bleeding when scales are removed) is characteristic 1. Diagnosis is typically clinical, but skin biopsy may show acanthosis, parakeratosis, and Munro microabscesses. Treatment options include:
- Topical therapies: corticosteroids, vitamin D analogs (calcipotriene), retinoids (tazarotene)
- Systemic therapies: methotrexate, cyclosporine, acitretin
- Biologics: TNF-α inhibitors (etanercept, adalimumab), IL-17 inhibitors (secukinumab), IL-23 inhibitors (guselkumab)
According to the most recent guidelines, the primary goal of treating patients with psoriatic arthritis is to maximize long-term health-related quality of life, through control of symptoms, prevention of structural damage, normalization of function, and social participation 1. The European League Against Rheumatism recommends a treatment approach based on the severity of the disease, with non-steroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and biologics used in a stepwise manner 1.
From the Research
Pathophysiology of Psoriasis
- Psoriasis is a chronic inflammatory disease with a strong genetic component 2
- The disease is characterized by a dysfunctional immune response with T-cells at the center of immunogenesis 2
- Triggers of the disease include factors such as trauma, obesity, infection, stress, and medications 2
- Psoriasis is a result of a complex interplay of genetic and immunological components, although the exact triggers and etiological factors are still unknown 3
Immunological Components
- T-cells play a central role in the immunogenesis of psoriasis 2
- Cytokines such as tumor necrosis factor (TNF-α), interleukin-12, interleukin-23, and interleukin-17 are responsible for psoriasis manifestations 2
- Biologic medications that target these cytokines have become an important component of care for treating moderate to severe psoriasis 2
Clinical Characteristics
- Psoriasis is characterized by discrete, erythematous scaly plaques, often found on extensor surfaces, especially the elbows and knees 2
- Lesions can affect any area of the skin, including the scalp, intertriginous areas, nails, palms, and soles 2
- Histologic findings of psoriasis include marked epidermal hyperplasia, dilated vessels within the dermal papilla, and elongated rete ridges 2