Journal of Clinical Case Reports

Erythema Multiforme (EM) is a benign hypersensitivity reaction characterized by multiple, erythematous, targetoid papules that appear most often symmetrically across the extremities. Histologically, the epidermis usually shows apoptotic keratinocytes, spongiosis, and hydropic changes. EM is associated with infections such as HSV and Mycoplasma pneumoniae and rarely with vaccinations and medications. It is an acute, self-limited disorder that resolves within 2-6 weeks. Recent studies report a variety of cutaneous findings status post mRNA COVID-19 vaccination with EM encompassing 1.1% of cutaneous findings. We report a case of a 39 y/o healthcare worker who developed acute erythema multiforme 10 days after receiving the third dose of the Moderna COVID-19 vaccine without prior adverse reactions to the first two doses. The diagnosis was made clinically, and the patient course was followed for 8 weeks without complete resolution.