Pyoderma Gangrenosum Induced by BNT162b2 COVID-19 Vaccine in a Healthy Adult.

(1) Background: Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis of unknown etiology. Coronavirus disease 2019 (COVID-19) vaccines can cause a variety of adverse cutaneous manifestations. PG associated with mRNA vaccines has not previously been described. This case study reports on the first patient to develop PG after receiving BNT162b2. (2) Case Presentation: An otherwise-healthy 27-year-old man developed multiple skin lesions 24 h after receiving the first dose of the messenger RNA-based Pfizer/BioNTech BNT162b2 COVID-19 vaccine. When in hospital, he developed a new painful ulcerative lesion on his right hand. Skin ulcer edge biopsy showed severe epidermal neutrophilic infiltrate with epidermal and dermal edema, underlying superficial dermal necrosis, and characteristic undermining with extensive mixed inflammatory infiltration of the dermis and abscess formation consistent with an ulcer with mixed dermal inflammation compatible with pyoderma gangrenosum. The lesion showed rapid improvement after the initiation of immunosuppressive therapy. (3) Conclusions: PG may be a rare adverse event related to the BNT162b2 vaccine, which could be more frequently encountered with the wide-scale use of mRNA vaccines. The continuous monitoring and surveillance of skin manifestations post-vaccination is essential.