Management of local and delayed cutaneous hypersensitivity reactions to anti-CGRP antibodies: implications for...

Delayed local skin reactions-appearing 24 to 48 h after subcutaneous injection-such as erythema, induration, pruritus, and pain, have been reported in patients receiving anti-Calcitonin Gene-Related Peptide monoclonal antibodies (anti-CGRP mAbs). Although typically mild to moderate in severity, these reactions can occasionally be intense and may lead to treatment discontinuation due to concerns from either the clinician or the patient.

We developed a structured tolerance protocol consisting of four steps: administration of an oral antihistamine and topical corticosteroid as pre-injection medication, prioritization of the abdominal area for subcutaneous monoclonal antibody administration, use of oral non-steroidal antinflammatory drugs (NSAID), cold compress post-injection, and continued topical and oral treatment as needed.

This protocol was applied to three patients who had previously experienced delayed skin reactions to erenumab, galcanezumab, or fremanezumab. With the use of the protocol, all three were able to continue treatment, with symptoms either markedly reduced or fully resolved.

This protocol offers a practical and effective approach to managing local skin reactions, promoting the continued use of anti-CGRP mAbs for migraine. Its simplicity facilitates implementation even in home-based care settings.