Cutaneous and systemic hyperinflammation drives maculopapular drug exanthema in severely ill COVID-19 patients

Background Coronavirus disease 2019 (COVID-19) has been associated with cutaneous findings, some being the result of drug hypersensitivity reactions such as maculopapular drug rashes (MDR). The aim of this study was to investigate whether COVID-19 is associated with the development of the MDR. Method Blood and skin samples from COVID-19 patients suffering from maculopapular drug rashes (COVID-MDR), healthy controls, non-COVID-19—related patients with drug rash with eosinophilia and systemic symptoms (DRESS), and MDR were analyzed. We utilized imaging mass cytometry (IMC) to characterize the cellular infiltrate in skin biopsies. Furthermore, RNA sequencing transcriptome of skin biopsy samples and high-throughput multiplexed proteomic profiling of serum were performed. Results IMC revealed by clustering analyses a more prominent, phenotypically shifted cytotoxic CD8+ T cell population and highly activated monocyte/macrophage (Mo/Mac) clusters in COVID-MDR. The RNA sequencing transcriptome demonstrated a more robust cytotoxic response in COVID-MDR skin. However, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was not detected in skin biopsies at the time point of MDR diagnosis. Serum proteomic profiling of COVID-MDR patients revealed up-regulation of various inflammatory mediators (IL-4, IL-5, IL-6, IL-8, IL-18, TNF, and IFN-γ), eosinophil and Mo/Mac -attracting chemokines (MCP-2, MCP-3, MCP-4 and CCL11). Analyses of cytokine networks demonstrated a relatively milder cytokine storm in DRESS compared to COVID-MDR, while MDR did not exhibit such features. Conclusion A massive systemic cytokine storm may promote activation of Mo/Mac and cytotoxic CD8+ T cells in severe COVID-19 patients, which in turn may impact the development of MDR.