Abstract
Background: Ocrelizumab, a humanized monoclonal antibody targeting CD20-positive B cells, is an effective disease-modifying therapy for multiple sclerosis (MS). While generally well-tolerated, alopecia areata (AA) has been reported as a rare adverse event, typically occurring within 3-4 months of treatment initiation. Limited data exist on the delayed onset of AA years after starting Ocrelizumab.
Case Presentation: We describe a 46-year-old female with relapsing-remitting MStreated with Ocrelizumab since 2019. Three months prior, she developed a solitary, well-circumscribed, non-scarring alopecic patch on her scalp. Dermatoscopy revealed exclamation mark hairs, indicative of AA. Initial treatment with intralesional corticosteroids (triamcinolone acetonide 2.5 mg/ml, 1.5 ml) and topical minoxidil 5% was initiated. Despite treatment, six additional alopecic patches appeared within a month. Subsequent management included further corticosteroid injections, continued minoxidil, and a brief course of oral prednisolone (25 mg daily for 14 days), resulting in hair regrowth. The patient reported a significant stressor before AA onset but had no personal or family history of autoimmune conditions.
Conclusion: This case illustrates the potential for delayed AA development in patients on long-term Ocrelizumab. While stress may be a contributing factor, the role of Ocrelizumab warrants further investigation. This case underscores the importance of monitoring for autoimmune complications in patients receiving long-term immunosuppressive therapies, highlighting the need for additional research on Ocrelizumab’s long term safety profile.

Key words: Ocrelizumab,Alopecia Areata,Relapsing-Remitting Multiple Sclerosis,Adverse Events,case report