Psoriasis is a chronic immune-mediated skin disorder characterized by erythematous, scaly plaques. We report a case of a 53-year-old male with a 12-year history of psoriasis and diabetes mellitus who presented with severe exacerbation following long-term corticosteroid use and subsequent cyclosporine therapy. The patient developed high-grade fever, widespread erythematous rashes with peeling, and severe itching, along with abnormal hematological findings. Initial management with cyclosporine and topical corticosteroids provided limited benefit, and abrupt withdrawal of prednisolone triggered a rebound flare due to a surge in pro-inflammatory cytokines. Cyclosporine therapy further led to paradoxical worsening of psoriasis, likely due to suboptimal response. The patient was subsequently initiated on ixekizumab, an IL-17A inhibitor, which demonstrated significant clinical improvement and near-resolution of psoriatic lesions. This case emphasizes the challenges in managing severe psoriasis in patients with prolonged corticosteroid exposure and highlights the role of biologic therapy as an effective treatment option in refractory cases.