HealthDay News — Localized injection-site reactions to the Moderna COVID-19 vaccine reported in 16 patients appear to be delayed hypersensitivity reactions, according to a study published in JAMA Dermatology.
Margaret S. Johnston, MD, from the Yale University School of Medicine in New Haven, Connecticut, and colleagues described the course of localized cutaneous injection-site reactions to the Moderna COVID-19 vaccine in a retrospective case series study. Sixteen patients were referred with localized cutaneous injection-site reactions from January 20 through February 12, 2021.
The researchers found that 14 of the patients self-identified as White and 2 as Asian. The delayed localized cutaneous reactions developed at a median of 7 days after receipt of the Moderna vaccine. These reactions occurred at or near the injection site; they were pruritic, painful, and edematous pink plaques. A mild predominantly perivascular mixed infiltrate with lymphocytes and eosinophils was identified on a skin biopsy specimen, which was consistent with a dermal hypersensitivity reaction. Of the 15 patients who had a reaction to the first vaccine dose, 11 developed a similar reaction to the second vaccine dose; 10 of these patients developed the second reaction sooner than they developed the reaction to the first dose.
“In contrast to immediate hypersensitivity reactions (eg, anaphylaxis and urticaria) that present within 4 hours of vaccine administration, these delayed localized hypersensitivity reactions are not a contraindication to subsequent vaccination,” the authors wrote.
One author disclosed financial ties to Johnson & Johnson.