Cutaneous Manifestations in Patients With Covid-19: A study of late onset rashes in hospitalized patients and literature review

Coronavirus disease 2019 (Covid-19), which is caused by the virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared by the World Health Organization (WHO) as the cause of the current pandemic in March 2020. The typical clinical presentation of Covid-19 includes upper respiratory tract symptoms (e.g., high fever, cough), fatigue, myalgias, diarrhea, and smell or taste disorders. In fact, non-cutaneous signs and symptoms have been the primary focus of the studies during the early days of the Covid-19 pandemic. Still, understanding this emergent disease required knowledge of all the possible disease manifestations in affected patients, including those pertaining to the skin. In fact, cutaneous manifestations have been increasingly reported in association with the pandemic, albeit the overall reports of dermatological cases being still scarce. Still, after the first description of Recalcati et al. in March 2020205, more studies regarding the cutaneous aspects of Covid-19 were published. Currently, the classification of the cutaneous manifestations of Covid-19 can be divided in two major categories: 1) Inflammatory and Exanthematous, or 2) Vasculopathic/ Vasculitic manifestations. Nonetheless, a crucial aspect of the cutaneous findings is their correlation to the timing of infection. More specifically, cutaneous lesions can be divided into those usually occurring during the prodromal phase of the disease (i.e., Urticarial lesions), during the first week of infection (i.e., Varicella-like and Morbilliform), and finally, late onset cutaneous lesions (e.g., purpuric, necrotic), which on the other hand, can be correlated to a worse prognosis. Finally, another spectrum of patients are those who developed a late onset cutaneous lesions when Covid-19 PCR resulted negative (e.g., Chilblain-like). Nonetheless, in literature, studies regarding late onset skin rash in Covid-19 patients after becoming PCR negative is still very limited. Recalcati et al. in a different study, described peculiar perniosis-like acral skin lesions in young healthy subjects with swab negativity in which he speculated them as a late manifestation of Covid-19 infection. Herrero-Moyano, M et al. were the first to describe a series of patients with a late-onset maculopapular rash speculating it to be linked to the cytokine storm of the hyperinflammatory phase caused by the virus or the drugs. Finally, Skroza, N et al. described a patient, who developed late onset urticarial lesions, 10 days after the first negative swab. Our primary aim is to describe ten patients, who after becoming negative for Covid-19 PCR test, developed a late onset skin rash. Part of these patients actually contributed to a study published in the European Journal of Dermatology by Brazzelli et al. Moreover, there will be a thorough analysis of these patients, describing their clinical features and their chronological analysis, laboratory and molecular tests, disease course and duration, date of onset of cutaneous manifestations and their corresponding latency with regards to the onset of Covid-19 symptoms. This is followed by a discussion and comparison of our findings to those present in the literature.