Abstract
A 62-year-old man presented to clinic with multiple erythematous, indurated papules coalescing into an annular plaque on the left upper arm. The lesions had been present for two weeks and first appeared one week after receiving the first dose of Pfizer-BioNTech COVID-19 vaccination. A punch biopsy was performed and revealed an essentially unremarkable epidermis with an underlying perivascular and interstitial lymphohistiocytic infiltrate within the papillary and upper reticular dermis. Lymphocytes appeared tightly cuffed around blood vessels. Eosinophils and neutrophils were also present around blood vessels and scattered throughout the interstitium. No definitive vasculitis was identified, however focal erythrocyte extravasation was present. A histopathological diagnosis of dermal hypersensitivity reaction was rendered and was considered to be a cutaneous sequela of the COVID-19 vaccine, given no other confounders were identified. Several hypersensitivity reactions have been reported following the COVID-19 vaccine ranging from mild cutaneous reactions, including redness and swelling at the injection site, to systemic anaphylaxis/anaphylactoid-type reactions. This delayed local reaction to Pfizer-BioNTech vaccine experienced in our patient appears to follow a similar pattern recently reported in a large cohort with a median of 7 days after first vaccination (PMID 33838206). Histologic data is limited, and our case adds to the growing body of literature on histologic reaction patterns that COVID-19 vaccine may elicit. Notably, the histopathologic features are also similar to what has been described in biopsies from patients with actual SARS-CoV-2 infection (so called Covid toes).
Financial Disclosure:
No current or relevant financial relationships exist.