Erythema Multiforme after BNT162b2 Vaccination.

A previously healthy 60-year-old woman presented with a 3-day history of pruritic eruption on the elbows. She had received the second dose of the BNT162b2 vaccine three days before the onset. An examination showed round edematous erythemas with central concavity symmetrically on the elbows (Picture 1). She had no mucosal lesions. These findings along with the histology (Picture 2) resulted in a diagnosis of erythema multiforme (EM). There were no other clinically identifiable causes, such as herpes simplex virus (HSV) or Mycoplasma pneumoniae infection. The lesions resolved with topical corticosteroid administration after a week. EM is an acute mucocutaneous hypersensitivity reaction that presents as multiform eruptions, including erythema, papules, bullous and erosive lesions, and characteristically, target lesions. The most common trigger (＞90% of cases) is infection, especially of HSV or M. pneumoniae (1). Regarding COVID-19, a relationship between EM and COVID-19 infection has been established (2). Therefore, the host immune response to SARS-CoV-2 that induces EM may be replicated by vaccination.

Picture 1.

Picture 2.

Patient consent was obtained from the patient.

The authors state that they have no Conflict of Interest (COI).