A Histologic Timeline of a Delayed Hypersensitivity Reaction after the COVID-19 Pfizer Booster.

A 54-year-old man presented with worsening bilateral rashes on legs and arms 7 days after receiving his BNT162b2 mRNA COVID-19 (Pfizer) vaccine booster. He developed burning on his palms about 5 days after receiving the booster. On day 6, he observed significant edema on his fingers and palms in addition to thin erythematous papules on his forearms.