Psoriasis

Psoriasis (PSORS) is a chronic, immune-mediated inflammatory skin disease, characterized by increased propagation of the epidermis with dilation of dermal capillaries. The major symptoms of psoriasis are itchy, scaly, and flaky skin, swelling, pain, and disfiguring skin lesions. Plaque psoriasis is the most common form. Other forms include flexural, guttate, nail, inverse psoriasis, erythroderma, and psoriatic arthritis. Nail psoriasis can accompany any form of psoriasis or occur of its own accord. It can occur in any age group, but psoriatic arthritis usually develops between the ages of 30-50 years. Various factors such as bacterial infection, genetic and environmental factors, and immune disorders play an important role in causing psoriasis. Psoriasis is associated with several comorbidities, including cardiovascular disease, lymphoma, and depression. Psoriasis is an immune-mediated disease with genetic predisposition, but no distinct immunogen has been identified. The presence of cytokines, dendritic cells, and T lymphocytes in psoriatic lesions has prompted the development of biologic therapies. The diagnosis is usually clinical, based on the presence of typical erythematous scaly patches, papules, and plaques that are often pruritic and sometimes painful. Biopsy is rarely needed to confirm the diagnosis. First-line therapies for most patients are topical treatments such as topical corticosteroids and vitamin D analogs. For those with more severe or treatment-resistant disease, second- or third-line therapies include phototherapy, systemic therapies such as methotrexate, and more recently biologic therapies such as tumour necrosis factor (TNF) inhibitors.