Dupilumab therapy for atopic dermatitis and aneurysmal subarachnoid hemorrhage: A case report and literature review.

Dupilumab is a human IgG4 monoclonal antibody that inhibits IL-4 and IL-13 signaling through IL-4Rα, thereby reducing Th2-mediated inflammation. Although it has demonstrated significant efficacy in the treatment of atopic dermatitis, its long-term vascular safety profile remains incompletely understood. We report a case of a 27-year-old male who developed sudden headache after physical exertion while receiving Dupilumab therapy for two years. Brain computed tomography revealed subarachnoid hemorrhage, and angiography demonstrated a ruptured dissecting aneurysm in the distal posterior cerebral artery. The patient underwent successful stent-assisted coil embolization, and follow-up imaging confirmed complete occlusion without neurological deficits. Dupilumab therapy was discontinued after the procedure. Although Dupilumab effectively suppresses allergic inflammation, chronic inhibition of the anti-inflammatory cytokines IL-4 and IL-13 signaling may theoretically influence vascular homeostasis through alterations in inflammatory pathways. Such mechanisms could potentially affect endothelial stability or thrombo-inflammatory balance. Given the inherent limitations of a single case report, a causal relationship cannot be established. However, this case raises the possibility of an association between prolonged Dupilumab therapy and cerebrovascular vulnerability, highlighting the need for further investigation into the vascular effects of long-term cytokine inhibition.