Paradoxical Behçet's Disease after Ixekizumab: A Case Report and Literature Review.

Behçet's disease is a chronic inflammatory condition that affects multiple organs and systems. It is characterized by recurrent oral and genital ulcers. A previous study reported that the IL-17A inhibitor secukinumab can improve the skin and mucosal manifestations in patients with refractory Behçet's disease. Additionally, secukinumab has been shown to effectively improve neurological symptoms when administered for Behçet's disease. However, we report a case where Behçet's disease occurred after the treatment of psoriasis with the IL-17A inhibitor ixekizumab. To summarize its clinical characteristics and treatment experience, we consulted relevant domestic and international literature and conducted a literature review. We concluded that anti-IL-17A treatment may lead to the development of Behçet's disease. The reported cases are more likely to occur in middle-aged men with varying onset times. The main manifestations include oral and vulvar mucosal ulcers. Furthermore, the gut microbiota may be involved in paradoxical Behçet's disease.