Classification and mitigation of negative injection experiences with biologic medications

Injection site reactions with biologic medications are encountered with variable frequency. Although there is no clear definition, they commonly manifest with pain and irritation at the injection site. Previously proposed reaction classification systems may be impractical or insufficient, and more intuitive nomenclature may benefit clinical dermatologists and patients. Negative injection experiences (NIE) are common reasons for biologic medication nonadherence. Here we provide clinical classifications and recommendations for mitigating these reactions. We categorized NIEs into the following: (a) physical, due to the needle and injection process, (b) irritant, related to properties of the injected solution, and (c) allergic, both immediate and delayed.