Psoriasis: An Updated Review of Pathophysiology, Clinical Spectrum, and Management

Psoriasis is a chronic, immune-mediated, multisystem disease characterized by well-demarcated, erythematous, and scaly plaques that affects an estimated 2–3% of the world’s population. Although classically considered a dermatologic disorder, psoriasis is increasingly recognized as a systemic inflammatory condition with substantial extracutaneous involvement, including psoriatic arthritis, cardiometabolic disease, nonalcoholic fatty liver disease, depression, and reduced health-related quality of life. Over the last two decades, fundamental insights into the interleukin (IL)-23/T helper (Th)17/TNF-α axis have reshaped the understanding of disease mechanisms and catalyzed the development of highly effective targeted therapies. Contemporary management integrates precise clinical phenotyping, validated measures of severity and patient-reported impact, and shared decision-making to achieve treat-to-target goals such as “clear” or “almost clear” skin and improved life participation. This narrative review synthesizes current evidence on the epidemiology, pathophysiology, clinical variants, diagnosis, and treatment of psoriasis; summarizes important advances including IL-23/IL-17 pathway inhibition and oral TYK2 inhibition; and highlights unresolved challenges such as persistent undertreatment, comorbidity prevention, long-term pharmacovigilance, and equitable global access. Five original figures illustrate the pathogenic immune cascade, clinical subtypes and body sites, severity assessment framework, a pragmatic treatment ladder, and the spectrum of systemic comorbidities. The aim is to provide an up-to-date, clinically relevant, and plagiarism-free overview suitable for academic submission and for informing multidisciplinary care.