Chilblains with CGRP monoclonal antibody treatment of chronic migraine: A case report and literature review

Background: Chilblains, characterized by swollen patches and blistering on peripheral extremities, commonly co-occur with Raynaud's Phenomenon. There is limited data to implicate CGRP-targeting migraine medications in these adverse events. Methods: We describe one patient who developed chilblains during treatment with the CGRP monoclonal antibodies erenumab followed by galcanezumab and review the current literature on similar outcome reporting. We conducted a literature review in reports of Raynaud's Phenomenon in patients treated with medications of this drug class. Results: A 38-year-old female patient developed chilblains while undergoing treatment with erenumab and then galcanezumab. The patient was transitioned to preventive treatment with rimegepant, which she has tolerated well without recurrence of chilblains. We also identified additional case reports, a cohort study, and an analysis of FAERS report data. Conclusion: The case reports suggest chilblains can be associated with treatment with CGRP monoclonal antibodies but not during treatment with a CGRP oral antagonist. This adds to the current awareness of potential microvascular complications of migraine therapy, but future safety studies are needed.