This article discusses a case study of a 15-year-old patient with juvenile psoriasis and primary immunodeficiency. The patient presented with erythematosquamous skin lesions, nail abnormalities, ankle pain and swelling, cough, and fever. Extensive investigations revealed a diagnosis of psoriasis vulgaris, severe psoriasis, and arthritis of the left ankle. The patient also exhibited hypogammaglobulinemia and a decreased count of switched memory B-cells, leading to a diagnosis of common variable immunodeficiency (CVID). Treatment with a biological agent, secukinumab, targeting interleukin-17 (IL-17), resulted in significant improvement in skin lesions and other symptoms. The case highlights the complexities of managing treatment for patients with a combination of autoimmune and immunodeficiency disorders. [Extracted from the article]