This study is a comparative clinical study evaluating the efficacy of combined therapy using cyclosporine and metformin versus cyclosporine alone in the treatment of psoriasis. Psoriasis is a chronic inflammatory skin disease that often requires systemic therapy in moderate to severe cases. Cyclosporine is an effective immunosuppressive agent; however, its long-term use is limited by potential adverse effects.

Metformin, a commonly used antidiabetic drug, has shown anti-inflammatory and immunomodulatory properties, which may enhance treatment outcomes in psoriasis. This study aims to assess whether adding metformin to cyclosporine improves clinical response compared to cyclosporine monotherapy.

Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by erythematous, scaly plaques and a relapsing course. It has a significant negative impact on patients' quality of life and is frequently associated with metabolic comorbidities, including insulin resistance and obesity. Management of moderate to severe psoriasis often requires systemic therapy to achieve adequate disease control.

Cyclosporine is a well-established systemic immunosuppressive drug used in the treatment of moderate to severe psoriasis due to its rapid onset of action and effectiveness in reducing disease severity. Its mechanism involves inhibition of T-cell activation and cytokine production. However, long-term use of cyclosporine is limited by potential adverse effects, particularly nephrotoxicity, hypertension, and metabolic disturbances. Therefore, strategies to enhance its efficacy while potentially allowing dose reduction are of clinical importance.

Metformin is an oral hypoglycemic agent widely used in the management of type 2 diabetes mellitus. Beyond its glucose-lowering effect, metformin has demonstrated anti-inflammatory, immunomodulatory, and antiproliferative properties. Recent evidence suggests that metformin may play a beneficial role in inflammatory and immune-mediated diseases, including psoriasis, through modulation of inflammatory cytokines and improvement of insulin resistance, which is commonly observed in psoriatic patients.

This study is designed as a comparative clinical study to evaluate the efficacy of combined therapy using cyclosporine and metformin versus cyclosporine monotherapy in the treatment of psoriasis. The primary objective is to assess whether the addition of metformin enhances the clinical response compared to cyclosporine alone. Treatment efficacy will be evaluated using standardized clinical assessment tools for psoriasis severity, along with monitoring of treatment safety and tolerability.

Inclusion Criteria:

• Patients ≥ 18 years old
• Patients of both genders
• Patients clinically diagnosed as moderate to severe psoriasis candidate for systemic treatment with Psoriasis Area Severity Index (PASI >10), Body Surface Area (BSA>10), Dermatology Life Quality Index (DLQI>10).(Laura Salgado-Boquete et al., 2021).
• Patients with new active lesions and also patient with chronic lesions (with periods of remission and exacerbation)

Exclusion Criteria:

• Erythrodermic and pustular psoriasis.
• Patients with systemic illness ( renal, hepatic and uncontrolled hypertension ).
• Pregnant and lactating females.
• Patients receiving systemic treatment relevant to psoriasis within 3 months before enrollment into the study or topical treatment relevant to psoriasis within 1 month before.
• Patients with other dermatological conditions.
• Patients with high uric acid level .