13/ The study offers a mechanistic explanation for both the increased incidence of primary chilblains during the pandemic and the absence of conventional markers of adaptive responses in affected individuals

11/ Chilblain lesions subsequently result from the infiltration of activated pDCs in acral skin, with I-IFN-mediated inflammation

10/ Patients’ pDCs exhibited cell-intrinsic hyperresponsiveness to TLR7 stimulation, but not TLR9, at odds with TLR7-deficient patients who are prone to life-threatening COVID-19 pneumonia

9/ We found that patients' leukocytes produced abnormally high levels of I-IFN when stimulated with ssRNA viruses, especially SARS-CoV-2, but not DNA viruses

6/ The temporal clustering of PC and COVID-19 cases suggests a causal link. However, most patients tested negative for SARS-CoV-2 by PCR and failed to mount detectable adaptive responses (overall IgG seroconversion <10%)

2/ Chilblains are inflammatory papules that appear on acral sites. First described in 1888, they have remained a medical mystery for more than a century

1/ One of the most intriguing enigmas of the #COVID19 pandemic was the sudden and unprecedented outbreak of chilblains that accompanied the early waves of #SARSCoV2 infections. Our new study in @jem.org uncovers the underlying immunological mechanism

rupress.org/jem/article/...