Abstract
Dupilumab is a humanized monoclonal antibody approved for the treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP), asthma, atopic dermatitis, eosinophilic esophagitis, and prurigo nodularis. The most common adverse reactions from dupilumab use are temporary injection site reactions and ocular surface reactions; however, a variety of both acute and delayed cutaneous reactions have also been described. We present a case of delayed hyperpigmented injection site reactions following chronic dupilumab use.