Acute urticarial rash after COVID-19 vaccination containing Polysorbate 80

We present the case of a 48-year-old Caucasian woman, who developed an acute urticarial rash after the second dose of coronavirus disease 2019 (COVID-19) vaccination with Oxford-AstraZeneca. Though the most common cutaneous adverse reactions to vaccines are non-allergic, we believe the rash may represent an immediate hypersensitivity type I reaction against the vaccine excipient Polysorbate 80 (Pol80), configuring an acute allergic urticaria. Skin prick test with Pol80, were performed and resulted positive, confirming the role of Pol80 in eliciting immediate hypersensitivity in our patient. Of note, sensitizing excipients contained in COVID-19 vaccines are commonly used in everyday products and preexisting sensitizations may cause allergic reactions to vaccines, highlighting the need to undergo allergy consultation upon vaccine administration.