Cutaneous manifestations of COVID-19 and COVID-19 vaccination.

In December 2019, a new infectious pathogen named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China. Transmitted through respiratory droplets, SARS-CoV-2 is the causative pathogen of coronavirus disease 2019 (COVID-19). Although this new COVID-19 infection is known to cause primarily interstitial pneumonia and respiratory failure, it is often associated with cutaneous manifestations as well. These manifestations with COVID-19 can be classified into seven categories: (i) chilblain-like skin eruption (e.g., COVID toes), (ii) urticaria-like skin eruption, (iii) maculopapular lesions, (iv) vesicular eruptions, (v) purpura, (vi) livedo reticularis and necrotic lesions, (vii) urticarial vasculitis, and others such as alopecia and herpes zoster. The pathogenesis of skin eruptions can be broadly divided into vasculitic and inflammatory skin eruptions. Various cutaneous adverse reactions have also been observed after COVID-19 mRNA vaccination. The major cutaneous adverse reactions are type I hypersensitivity (urticaria and anaphylaxis) and type IV hypersensitivity (COVID arm and erythema multiform). Autoimmune-mediated reactions including bullous pemphigus, vasculitis, vitiligo, and alopecia areata have also been reported. Several cases with chilblain-like lesions and herpes zoster after COVID-19 mRNA vaccination have been published. Various skin diseases associated with COVID-19 and COVID-19 vaccination have been reported, and the mechanism has been partly elucidated. In the process, for example, some papers have reported that it is not related to COVID-19 infection, although it was initially called COVID-toe and considered a COVID-19-associated cutaneous eruption. In fact, some COVID-19-associated skin reactions are indistinguishable from drug eruptions. In the future, the mechanisms of COVID-19- or COVID-19 vaccine-associated skin reactions need to be elucidated and verification of causal relationships is required.

Management of urticaria in COVID-19 patients: A systematic review.

The global pandemic COVID-19 has resulted in significant global morbidity, mortality and increased healthcare demands. There is now emerging evidence of patients experiencing urticaria. We sought to systematically review current evidence, critique the literature, and present our findings. Allowing PRISMA guidelines, a comprehensive literature search was carried out with Medline, EMBASE, Scopus, Cochrane, and Google Scholar, using key MeSH words, which include "COVID-19," "Coronavirus," "SARS-Cov-2," "Urticaria," "Angioedema," and "Skin rash" up to 01 August 2020. The key inclusion criteria were articles that reported on urticaria and/or angioedema due to COVID-19 infection and reported management and outcome. Studies were excluded if no case or cohort outcomes were observed. Our search returned 169 articles, 25 of which met inclusion criteria. All studies were case reports, reporting 26 patients with urticaria and/or angioedema, COVID-19 infection and their management and/or response. ajority of patients (n = 16, 69%) were over 50 years old. However, urticaria in the younger ages was not uncommon, with reported case of 2 months old infant. Skin lesions resolved from less than 24 hours to up to 2 weeks following treatment with antihistamines and/or steroids. There have been no cases of recurrent urticaria or cases nonresponsive to steroids. Management of urticarial in COVID-19 patients should involve antihistamines. Low dose prednisolone should be considered on an individualized basis. Further research is required in understanding urticarial pathogenesis in COVID-19. This will aid early diagnostic assessment in patients with high index of suspicion and subsequent management in the acute phase.