plakkpsoriasis

Plakkpsoriasis, commonly called plaque psoriasis, is the most common form of psoriasis, a chronic autoimmune skin condition. It presents as well-defined red, scaly plaques, usually on the elbows, knees, scalp, and lower back. The condition affects an estimated 2-3% of people worldwide and often begins in adolescence or early adulthood.

Pathophysiology and presentation: Plaque psoriasis is driven by immune-mediated inflammation. T cells activate keratinocytes, leading to rapid skin cell turnover and thick, silvery plaques. Genetic predisposition and environmental triggers contribute. Cytokines such as TNF-alpha, IL-17, and IL-23 play central roles. Nails may show pitting or onycholysis, and some people develop psoriatic arthritis.

Diagnosis and variants: Diagnosis is typically clinical; biopsy is rarely required. Plaque psoriasis is the most common subtype; other forms include guttate, inverse, pustular, and erythrodermic psoriasis. Triggers include infections (notably streptococcal), stress, skin injury (Koebner phenomenon), certain medications, and alcohol. Comorbidities include psoriatic arthritis, obesity, metabolic syndrome, and cardiovascular risk.

Treatment and prognosis: Management depends on severity and affected areas. Mild disease responds to topical corticosteroids and vitamin D analogs; scalp and nails may need specialized formulations. Phototherapy (narrowband UVB) helps for moderate disease. Systemic therapies such as methotrexate, cyclosporine, or retinoids are used for extensive disease, and biologics targeting TNF, IL-17, or IL-23 are options for many patients. The disease is typically chronic with periods of remission and flare; ongoing care focuses on symptom control and reducing comorbidity risk.