الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Psoriasis is a chronic skin disorder characterized by infiltration of inflammatory elements, keratinocyte hyperproliferation and altered differentiation. patients typically present with red , scaly, raised plaques occurring mostly on the scalp and the extensor surfaces, such as knees and elbows. Psoriasis affects about 25 million persons in North America and Europe, and is probably the most prevalent immune-mediated skin disease in adults. It is organ espcific and is triggered by an activated cellular immune system .As with other immune-mediated diseases, such as Crohns disease, rheumatoid arthritis, multiple sclerosis, and juvenileonset diabetes, psoriasis is regarded as a T-cell mediated auto-immune disease There is considerable geographic variation in the prevalence of psoriasis; in the UK, it is found in about 1.4–1.6% of the population, but it seems to be less common in, for example, China and Japan. Males and females are affected equally. The age of onset shows a bimodal distribution, with the largest peak in the second decade and another at about 50 years of age. Regardless of the type of psoriasis therapy used,
numerous factors can further exacerbate psoriasis, including infection,
endocrine factors, hypocalcemia, medications, psychologic stress, or local trauma. Furthermore, alterations in treatment modalities can result in ongoing cycles of remission and exacerbation. Psoriasis therapy is not optimal, and the selection of therapy depends on the extent and psychosocial impact of the disease Current therapies for psoriasis include topical and systemic therapies, which includes several immunosuppressive drugs and more recently potent T cell immunomodulators Topical therapy forms the corner stone in the management of psoriasis and of significant value monotherapy in mild to moderate psoriasis, it is used predominantly as adjunctive therapy in moderate and severe forms of the disease. It includes keratolytics, coal tar, corticosteroids, dithranol, retinoids, and synthetic vitamin D and emollients,new modalities in topical treatment include application Acitretin loaded nanostructured lipid carriers to avoid the side effects of the plain acitretin gel another modality is novel benzoxaborole anti-inflammatory agent (AN2728) this agent exhibit inhibitory activity against the release of cytokines, such as TNF-a and IFN-c,and also inhibited the PDE4 enzyme as part of its mechanism of action and the topical application of anti-angiogenic peptides based on pigment epithelium-derived factor Phototherapy is used in the treatment of patients with moderate to severe psoriasis. options include UVA, UVB, narrow band UVB (NB-UVB), psoralens plus UVA (PUVA), and retinoids plus PUVA (Re-PUVA). Both broad band and narrow band UVB effect have immunosuppressive action by depleting dermal and epidermal T cells in psoriatic lesions, possibly by increasing apoptosis Moreover, UVB alters the T1/T2 cytokine profile by long-term risks of skin cancer and the more recent Excimer laser , monochromatic excimer Light and targeted phototherapy Excimer laser is particularly useful in localized lesions Involving less than 10% of body surface area, in small children,in non-exposed sites (scalp, ears, axillae, groin, intergluteal cleft), in resistant sites(elbows and knees, lower legs and ankles, chronic lesions induced by trauma known as koebner lesions, palms with thin lesions) and insituations and also pulsed dye laser which show good result in psoriasis treatment and the relatively recent photodynamic therapy.
Systemic treatment include methotrexate retinoids cyclosporine and the less commeniy used azathioprine, fumaric acid esters Hydroxy urea Leflunomide, mycophenolate mofetil, Sulfasalazine, Tacrolimus and 6 Thioguanine.
Biologic therapies (monoclonal antibodies and receptor–antibody fusion proteins). Can potentially limit adverse systemic side effects because of their high specificity directed towards pathogenic cells without affecting cells of other organs. By initiating treatment at an earlier point in the inflammatory cascade in immune diseases, biologic therapies have the benefit of halting tissue damage associated with irreversible changes that affect quality of life and morbidity.
They include Alefacept, Efalizumab, Etanercep, Infliximab,
Adalimumab Another trend in the biological treatment is the bevacizumab (monoclonal antibody against VEGF) provides a very attractive target for therapeutic intervention in psoriatic inflammation and consequently topical or systemic therapies directed against VEGF or its receptors might offer a novel approaches in psoriasis treatment which warrant further research and testing in larger clinical trials An emerging immunologic target for psoriasis therapy is the shared p40 subunit of interleukin (IL)- 12and-23.ABT-874 (Abbott Laboratories, Abbott Park, IL) is a human monoclonal antibody with high affinity for the p40 subunit of IL-12/23 which is an efficacious and safe treatment option for treatment and retreatment of moderate to severe chronic plaque psoriasis.
The trend for anti-cytokine therapies in the treatment of psoriasis continues in targeting even more specific components of the IL-23/ Th17 pathway. this refinement of cytokine targeting is an attempt to suppress pathogenic immunity as selectively as possible so as to minimize the potential negative effects associated with broad immunosuppression.