Rare Skin Reactions Following COVID-19 Vaccines Are Being Studied

May 5, 2021

Recent findings from the COVID-19 Dermatology Registry, run by the American Academy of Dermatology (AAD) and the International League of Dermatologic Societies, helped shed some light on the skin reactions reported after Moderna and Pfizer COVID-19 vaccinations in some individuals. In this study, 414 cutaneous reactions were reviewed, ranging from minor injection-site inflammation to an episode of shingles.

This research is unique because it delves into a whole range of reactions that had not been reported in vaccine clinical trials. Detailed information was collected from registry participants, including which type of vaccine was received and when and the morphology, timing, duration, and treatment of the skin reactions. The most common morphologies seen in this study were “delayed large local reactions, local injection site reactions, urticaria, and morbilliform eruptions.”

The skin reaction seen most often following the Moderna vaccine was urticaria, also known as hives. Researchers have found that in 50% of patients who experience chronic idiopathic urticaria, the immune system behaves erratically and attacks the body’s normal tissues, causing hives. Could this be the same mechanism happening in these rare cases following the COVID-19 vaccine? What can these post-vaccine reactions tell us about the field of autoimmunity as a whole? While we wait for scientists to uncover these answers, the good news is that none of the patients who had skin reactions reported severe adverse events, and less than half did not experience a recurrence with their second dose.