A Histologic Timeline of a Delayed Hypersensitivity Reaction after the COVID-19 Pfizer Booster.

A 54-year-old man presented with worsening bilateral rashes on legs and arms 7 days after receiving his BNT162b2 mRNA COVID-19 (Pfizer) vaccine booster. He developed burning on his palms about 5 days after receiving the booster. On day 6, he observed significant edema on his fingers and palms in addition to thin erythematous papules on his forearms. On day 7, he developed edema on his bilateral dorsal feet, and thin erythematous plaques on his shins. He stated that the rashes were pruritic. He had no rashes following the first two doses of the Pfizer vaccine. He denied having any history of skin disease, autoimmune disease, or allergies. Physical examination revealed multiple thin erythematous papules coalescing into thin plaques on his flexor forearms, and thin erythematous plaques on his dorsal feet (Figure 1). Three 4-mm punch biopsies were performed on his left flexor forearm. The biopsies were carried out at papules present for different lengths of time. Papules at biopsy sites "A," "B," and "C" were present for approximately 24-36 hours, 12-18 hours, and 3-6 hours, respectively (Figure 1).

SARS-CoV-2 and Skin: The Pathologist's Point of View.

The SARS-CoV-2 pandemic has dramatically changed our lives and habits. In just a few months, the most advanced and efficient health systems in the world have been overwhelmed by an infectious disease that has caused 3.26 million deaths and more than 156 million cases worldwide. Although the lung is the most frequently affected organ, the skin has also resulted in being a target body district, so much so as to suggest it may be a real "sentinel" of COVID-19 disease. Here we present 17 cases of skin manifestations studied and analyzed in recent months in our Department; immunohistochemical investigations were carried out on samples for the S1 spike-protein of SARS-CoV-2, as well as electron microscopy investigations showing evidence of virions within the constituent cells of the eccrine sweat glands and the endothelium of small blood vessels. Finally, we conduct a brief review of the COVID-related skin manifestations, confirmed by immunohistochemistry and/or electron microscopy, described in the literature.

[Cutaneous Manifestations Associated with COVID-19: A Narrative Review]. / Manifestações Cutâneas Associadas à COVID-19: Uma Revisão Narrativa.

INTRODUCTION: COVID-19 is an infectious disease caused by the new coronavirus, SARS-CoV-2, that has spread rapidly throughout the world. This has resulted in an urgent need to obtain information regarding its pathogenesis, diagnosis and clinical manifestations. More specifically, skin manifestations, seldom reported initially, have been increasingly described. MATERIAL AND METHODS: We performed a literature search in the PubMed database, regarding cutaneous manifestations associated with COVID-19. This article describes the clinical and histological findings of the main skin lesions observed in the context of SARS-CoV-2 infection. DISCUSSION: Cutaneous manifestations associated with COVID-19 have been described in multiple retrospective and prospective studies, case series and case reports. The reported incidence reached 20.4%. Although there was substantial heterogeneity in terms of clinical patterns, the main ones include: erythematous/maculopapular, urticarial, papulovesicular, and purpuric/petechial eruptions, chilblain-like lesions and livedoid/acro-ischemic lesions. In the vast majority, the underlying pathophysiologic mechanisms are not fully understood, although histopathological findings and biomolecular studies can add relevant data. CONCLUSION: The recognition of cutaneous manifestations associated with COVID-19 is of utmost importance. They may help establishing an early diagnosis, namely in oligosymptomatic patients or when confirmatory tests are impossible to perform. Moreover, chilblain-like lesions and acro-ischemia, also seem to play an important role in terms of prognosis.

Introdução: A COVID-19, doença infeciosa causada por um novo coronavírus, SARS-CoV-2, propagou-se rapidamente pelo mundo inteiro, resultando numa necessidade emergente de obtenção de conhecimentos alusivos à sua patogénese, diagnóstico e sintomatologia. Mais especificamente, um número cada vez maior de casos relativos a manifestações cutâneas, previamente desconhecidas, tem vindo a ser descrito.Material e Métodos: Foi realizada uma pesquisa de literatura, através da base de dados PubMed, referente às manifestações dermatológicas associadas à COVID-19. O presente artigo descreve os achados clínicos e histológicos das principais lesões cutâneas observadas em contexto da infeção por SARS-CoV-2.Discussão: Manifestações cutâneas associadas à COVID-19 foram descritas em múltiplos estudos retrospetivos e prospetivos, séries de casos e casos clínicos isolados. A incidência reportada atingiu os 20,4%, verificando-se uma heterogeneidade de padrões clínicos substancial. Destes destacam-se as erupções eritematosas/maculopapulares, urticariformes, papulovesiculares, purpúricas/petequiais, lesões tipo-perniose e lesões livedóides/acro-isquémicas. O conhecimento dos mecanismos fisiopatológicos subjacentes tem vindo a ser enriquecido com achados os histológicos e de biologia molecular.Conclusão: É essencial o reconhecimento das manifestações dermatológicas associadas à COVID-19, uma vez que podem permitir o diagnóstico precoce da infeção, nomeadamente em casos oligossintomáticos ou quando não é possível a realização de testes confirmatórios. Embora menos estabelecido, lesões tipo-perniose e acro-isquémicas, parecem ter também um papel importante a nível prognóstico.

Acute acral eruptions in children during the COVID-19 pandemic: Characteristics of 103 children and their family clusters.

BACKGROUND: A marked increase in frequency of acute acral eruptions (AAE) was observed in children during the COVID-19 pandemic in the spring period. OBJECTIVES: In this observational multicenter study, based on children with AAE, we aimed to assess the proportion of household members possibly infected by SARS-CoV-2. METHODS: We collected data from all children observed with AAE, prospectively from April 7, 2020 to June 22, 2020, and retrospectively since February 28, 2020. The primary outcome was the household infection rate, defined as the proportion of family clusters having at least one member with COVID-19 infection other than the child with AAE ("index child"). The definition of a case was based on characteristic clinical signs and a positive PCR or serology. RESULTS: The study included 103 children in 10 French departments and in Quebec. The median age was 13 years and the interquartile range [8-15], with a female-to-male ratio of 1/1.15. In children with AAE, all PCR tests were negative (n=18), and serology was positive in 2/14 (14.3%) cases. We found no significant anomalies in the lab results. A total of 66 of the 103 families (64.1%) of included children had at least one other infected member apart from the index child. The total number of household members was 292, of whom 119 (40.8%) were considered possibly infected by SARS-CoV-2. No index children or households exhibited severe COVID-19. DISCUSSION: Among the 103 households included, 64.1% had at least one infected member. Neither children with AAE nor their households showed severe COVID-19.

First neonates with severe acute respiratory syndrome coronavirus 2 infection in Romania: Three case reports.

RATIONALE: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which quickly spread throughout the world, has been putting medical workers all over the world in difficulty because of the high number of cases combined with the lack of information about the disease. Although pediatric cases are rare, the group age under 12 months has been in general more susceptible to develop severe forms of the disease compared with the patients in the age interval of 1 to 18 years. PATIENT CONCERNS: Three newborns have been tested positive for SARS-CoV-2 infection. One of them presented bilateral decreased air entry, while the other 2 had no respiratory symptomatology. All 3 developed diaper erythema and oral candidiasis. DIAGNOSIS: For building up the report, newborns that were positive for coronavirus disease 2019 (COVID-19) infection were included in the case series. The chest X-ray of the symptomatic patient revealed a medium degree of hilar parenchymal infiltration and a slight infiltration of the visceral pleura. INTERVENTIONS: The patients were admitted in our isolated neonatology ward. All of them received antifungal treatment for the oral candidiasis and topic cream for diaper erythema. The symptomatic patient also received prophylactic antibiotherapy, human immunoglobulins, aminophylline, and parenteral nutrition. OUTCOMES: All 3 neonates were discharged after 2 consecutive negative tests for SARS-CoV-2. Patients 1 and 2 fully recovered, whereas the condition of patient 3 improved. LESSONS: Even if there are only a few reported cases of neonates infected with COVID-19 and most of them present mild manifestations, newborns need a more careful insight because of the nonspecific symptomatology.

Lessons from dermatology about inflammatory responses in Covid-19.

The SARS-Cov-2 is a single-stranded RNA virus composed of 16 non-structural proteins (NSP 1-16) with specific roles in the replication of coronaviruses. NSP3 has the property to block host innate immune response and to promote cytokine expression. NSP5 can inhibit interferon (IFN) signalling and NSP16 prevents MAD5 recognition, depressing the innate immunity. Dendritic cells, monocytes, and macrophages are the first cell lineage against viruses' infections. The IFN type I is the danger signal for the human body during this clinical setting. Protective immune responses to viral infection are initiated by innate immune sensors that survey extracellular and intracellular space for foreign nucleic acids. In Covid-19 the pathogenesis is not yet fully understood, but viral and host factors seem to play a key role. Important points in severe Covid-19 are characterized by an upregulated innate immune response, hypercoagulopathy state, pulmonary tissue damage, neurological and/or gastrointestinal tract involvement, and fatal outcome in severe cases of macrophage activation syndrome, which produce a 'cytokine storm'. These systemic conditions share polymorphous cutaneous lesions where innate immune system is involved in the histopathological findings with acute respiratory distress syndrome, hypercoagulability, hyperferritinemia, increased serum levels of D-dimer, lactic dehydrogenase, reactive-C-protein and serum A amyloid. It is described that several polymorphous cutaneous lesions similar to erythema pernio, urticarial rashes, diffuse or disseminated erythema, livedo racemosa, blue toe syndrome, retiform purpura, vesicles lesions, and purpuric exanthema or exanthema with clinical aspects of symmetrical drug-related intertriginous and flexural exanthema. This review describes the complexity of Covid-19, its pathophysiological and clinical aspects.