Oral Candidiasis in a Migraine Patient Taking Erenumab and Galcanezumab: a Case Report

Currently, there are three FDA-approved injectable calcitonin gene-related peptide (CGRP) antagonists, namely erenumab-aooe, galcanezumab-gnlm, and fremanezumab, all approved in 2018. There is no documented evidence of any fungal infections with these medications. We report a patient with oral candidiasis after administration of erenumab and galcanezumab for migraine headaches. Per the literature, the presence of candida stimulates sensory neural tissue to release CGRP, which then in turn leads to the signaling of dendritic cells to release vital cytokines such as interleukin-23 (IL-23) (Kashem et al. in Trends Immunol. 37(7):440–50, 2016). CGRP is involved in the cutaneous exposure to antigens, leading to its release and subsequent signaling pathway. The disruption of this cascade could lead to a decrease in the innate immune response to candida infection, thus leading to its proliferation. A 48-year-old female with a diagnosis of migraine headache presents with oral candidiasis after anti-CGRP medications, erenumab, and galcanezumab, an adverse effect not yet reported to our knowledge. Long-term anti-CGRP effects on human physiology are not yet understood due to the relatively novelty of these medications. We review the literature to support our proposition that CGRP is involved in antifungal immunity, and its antagonism incurs susceptibility to candidiasis.