Faculty Bibliography

BACKGROUND:As more people become vaccinated against the SARS-CoV-2 virus, reports of delayed cutaneous hypersensitivity reactions are beginning to emerge. METHODS:In this IRB-approved retrospective case series, biopsies of potential cutaneous adverse reactions from the Pfizer-BioNTech or Moderna mRNA vaccine were identified and reviewed. Clinical information was obtained through the requisition form, referring clinician, or medical chart review. RESULTS:Twelve cases were included. Histopathological features from two injection site reactions showed a mixed-cell infiltrate with eosinophils and a spongiotic dermatitis with eosinophils. Three biopsies came from generalized eruptions that demonstrated interface changes consistent with an exanthematous drug reaction. Three biopsies revealed a predominantly spongiotic pattern, consistent with eczematous dermatitis. Small vessel vascular injury was seen in two specimens, which were diagnosed as urticarial vasculitis and leukocytoclastic vasculitis, respectively. There were two cases of new-onset bullous pemphigoid supported by histopathological examination and direct immunofluorescence studies. Eosinophils were seen in 10 cases. CONCLUSIONS:Dermatopathologists should be aware of potential cutaneous adverse reactions to mRNA-based COVID-19 vaccines. Histopathological patterns include mixed-cell infiltrates, epidermal spongiosis, and interface changes. Eosinophils are a common finding but are not always present. Direct immunofluorescence studies may be helpful for immune-mediated cutaneous presentations such as vasculitis or bullous pemphigoid. This article is protected by copyright. All rights reserved.

ABSTRACT/UNASSIGNED:Papillary dermal elastolysis has been described in the setting of experimental combination nivolumab and cabiralizumab immunotherapy. We report a third patient with distinctive, generalized atrophic macules that developed after a morbilliform eruption during a clinical trial for treatment of metastatic pancreatic adenocarcinoma. Histopathological findings demonstrated diminished elastic fibers in the papillary dermis, associated with a histiocyte-rich infiltrate and increased dermal mucin, features that should clue the dermatopathologist to this condition.