Original StudyHistopathological and Immunohistochemical Characterization of Skin Biopsies From 41 SARS-CoV-2 (+) Patients: Experience in a Mexican Concentration Institute: A Case Series and Literature ReviewQuintero-Bustos, Gabriel MD; Aguilar-Leon, Diana PhD; Saeb-Lima, Marcela MD Author Information Pathology Department, National Institute of Medical Sciences and Nutrition Salvador Zubiran, Mexico City, Mexico. Correspondence: Marcela Saeb-Lima, Vasco de Quiroga 15, Tlalpan, Mexico City (e-mail: [email protected]). Supported by the Pathology Department, National Institute of Medical Sciences and Nutrition Salvador Zubiran, and personal contributions from the authors. M. Saeb-Lima and G. Quintero-Bustos contributed to the background work and conceived the experiments. G. Quintero-Bustos organized and analyzed the results. D. Aguilar-Leon contributed to the design and performed the experimental work. G. Quintero-Bustos and M. Saeb-Lima wrote the manuscript. M. Saeb-Lima provided the funds. M. Saeb-Lima, G. Quintero-Bustos, and D. Aguilar-Leon contributed equally to this research project. The authors declare no conflicts of interest. Committee for Ethics in Research of the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, approval: PAT-3469-20-21-1. The procedures that were used for the protocol were in accordance with the ethical standards of the responsible committee on human experimentation (institutional or regional) and with the Helsinki Declaration of 1975, as revised in 1983. The data sets generated for this study are available on request to the corresponding author. The American Journal of Dermatopathology: May 2022 - Volume 44 - Issue 5 - p 327-337 doi: 10.1097/DAD.0000000000002151 Buy Metrics Abstract The SARS-CoV-2 pandemic brought countless clinical and pathophysiological questions. Although mucocutaneous infections are the most visible, they are among the least studied. This article provides relevant information to characterize morphologically and immunohistochemically the dermatoses from patients with COVID-19, during the first year of the pandemic. Immunohistochemistry reactions against the spike protein were performed in 48 skin biopsies, and the positive cases were classified according to their histomorphology; at the end, 41 biopsies led us to identify 12 morphological patterns that mimic other skin pathologies, among which pityriasiform patterns predominate. For the literature review, we selected cases of SARS-CoV-2 dermatoses that included complete histopathological information and that were published during the same interval of time; after careful evaluation, 205 biopsies were selected and then classified into 8 groups according to previously published proposals. Dermatoses associated with SARS-CoV-2 are as diverse in their clinical expression as in their histopathology, mimicking entities totally unrelated to COVID-19. Furthermore, some of these groups are characteristically associated with an aggressive course of the disease. Undoubtedly, it is necessary to delve into the possibility that these findings are translatable into prognostic and therapeutic factors. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.