OBJECTIVE Secukinumab (SEC) is an effective and widely used drug in psoriatic disease and axial spondyloarthritis. However, SEC has been found to be associated with inflammatory conditions and vasculitis. These inflammatory adverse effects may complicate the treatment of underlying disease, and clinicians may experience difficulties in recognizing and managing this unusual condition. METHODS A man aged 56 years with psoriatic disease refractory to conventional disease-modifying antirheumatic drugs was given adalimumab for 6 weeks, then switched to SEC when his psoriatic lesions were exacerbated. After 3 weeks of SEC treatment, he developed systemic features of IgA vasculitis while his skin lesions and arthritis persisted. CONCLUSIONS Although SEC-related inflammatory adverse events, including vasculitis, are rarely encountered in clinical practice, it is essential to recognize them because they can be mistaken as a component of the underlying inflammatory disease. In addition, the dramatic improvement in many cases after the cessation of SEC underlines the importance of making an accurate diagnosis. Pathogenetically, these adverse events are likely to be paradoxical reactions, except for SEC-induced inflammatory bowel diseases. However, in many aspects, their pathogenesis is controversial and needs clarification.