Psoriasis. Definition and Classification of A Complex Entity

Abstract

Psoriasis, a chronic inflammatory skin condition influenced by hereditary factors and immune system response, exhibits diverse clinical manifestations. While its global incidence is around 2%, prevalence varies across geographical regions and ethnicities. The most common form, psoriasis vulgaris, presents as red, itchy patches with silver-colored scales, predominantly affecting the trunk, limbs, and scalp. Other clinical subtypes include inverse psoriasis, guttate psoriasis, pustular psoriasis, and erythrodermic psoriasis, each with distinct features and impacts. Beyond skin manifestations, psoriasis is associated with various co-occurring medical conditions, including hyperlipidemia, hypertension, coronary artery disease, type 2 diabetes, and obesity. Psoriasis patients have an increased risk of cardiovascular disease, with severity correlating with the incidence of diabetes and cardiovascular events. Additionally, psoriatic arthritis affects around 40% of patients and is often accompanied by nail involvement. Recent studies utilizing imaging techniques like 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) and nuclear magnetic resonance spectroscopy have shed light on systemic inflammation and cardiovascular risk in psoriasis patients. Treatments targeting IL-23 and IL-17 have shown promising results, though long-term efficacy and drug survival remain areas of concern. Psoriasis profoundly impacts patients' quality of life, with psychological distress comparable to cancer and depression. However, treatment can significantly alleviate symptoms and improve overall well-being. Ongoing research aims to expand treatment options, particularly targeting novel molecular pathways. In conclusion, while significant progress has been made in understanding and treating psoriasis, challenges remain in optimizing therapy selection and long-term management. Further research is warranted to elucidate the complex genetic and immunological underpinnings of the disease and to enhance treatment outcomes for affected individuals