SARS-CoV-2 detection by digital polymerase chain reaction and immunohistochemistry in skin biopsies from 52 patients with different COVID-19-associated cutaneous phenotypes.

BACKGROUND: COronaVIrus Disease 19 (COVID-19) is associated with a wide spectrum of skin manifestations, but SARS-CoV-2 RNA in lesional skin has been demonstrated only in few cases. OBJECTIVE: To demonstrate SARS-CoV-2 presence in skin samples from patients with different COVID-19-related cutaneous phenotypes. METHODS: Demographic and clinical data from 52 patients with COVID-19-associated cutaneous manifestations were collected. Immunohistochemistry and digital PCR (dPCR) were performed in all skin samples. RNA in situ hybridization (ISH) was used to confirm the presence of SARS-CoV-2 RNA. RESULTS: Twenty out of 52 (38%) patients presented SARS-CoV-2 positivity in the skin. Among these, 10/52 (19%) patients tested positive for spike protein on immunohistochemistry, five of whom had also positive testing on dPCR. Of the latter, one tested positive both for ISH and ACE-2 on immunohistochemistry while another one tested positive for nucleocapsid protein. Twelve patients showed positivity only for nucleocapsid protein on immunohistochemistry. CONCLUSIONS: SARS-CoV-2 was detected only in 38% of patients, without any association with a specific cutaneous phenotype, suggesting that the pathophysiology of cutaneous lesions mostly depends on the activation of the immune system. The combination of spike and nucleocapsid immunohistochemistry has higher diagnostic yield than dPCR. Skin persistence of SARS-CoV-2 may depend on timing of skin lesions, viral load and immune response.

Papulo-purpuric dermatitis of childhood: a distinct PLEVA-like eruption associated to SARS-CoV-2 infection. Clinical, histopathological and immunohistochemical study of 10 cases.

We observed ten children with a papular eruption with purpuric features during the SARS-CoV-2 pandemic in Northern Italy (May-December 2020). Histological examination showed signs of SARS-CoV-2-related dermatosis. Evidence of nucleocapsid viral proteins using SARS-CoV-2 (2019-nCoV) nucleocapsid antibody revealed cuticular staining of the deep portion of the eccrine glands in all cases.

Similarities in Cutaneous Histopathological Patterns between COVID-19-positive and COVID-19 High-risk Patients with Skin Dermatosis.

Only recently histopathological studies of patients with dermatosis and concomitant SARS-Cov-2 viral infection were published. Seven months into the COVID-19 pandemic, more skin biopsies of COVID-19 positive patients are taking place. We examined the histological features of 30 skin biopsies from two groups of patients: Ten specimens of patients tested positive for COVID-19 with an active systemic infection and associated dermatosis. Twenty specimens were from patients not considered COVID-positive (due to PCR swab negativity or not tested at all) with cutaneous lesions either showing viral infection symptoms (fever, cough, ageusia and severe immunocompromised condition due to HIV infection and malignancies), or presented a high risk of being infected (such as cohabitation with COVID-19 positive parents and siblings with simultaneous chilblains). This study analyses the histological and immunohistochemical (SARS-CoV-2 2019-nCoV nucleocapsid antibody) characteristics of the two groups and identifies 4 histopathological patterns. The histopathological features of the two groups present similar features that may help to identify an ongoing COVID-19 infection even in asymptomatic carriers with dermatosis.

Histopathological Study of a Broad Spectrum of Skin Dermatoses in Patients Affected or Highly Suspected of Infection by COVID-19 in the Northern Part of Italy: Analysis of the Many Faces of the Viral-Induced Skin Diseases in Previous and New Reported Cases.

Skin manifestations of COVID-19 infections are diverse and are new to the dermatology community. We had the opportunity to examine the clinical and histopathological features of several patients who were divided into 3 groups. The first group included 8 COVID-19-positive patients who were hospitalized and quarantined at home. The second group included children and young adults who presented with chilblain erythema, erythema multiforme, and urticaria-like lesions. This group of patients was negative for the COVID-19 gene sequences by polymerase chain reaction but had a high risk of COVID-19 infection. The third group included clinically heterogeneous and challenging lesions. These patients were not subject to either polymerase chain reaction tests or serological analyses because they sought dermatological attention only for a dermatosis. The histopathological analysis of these cases showed a wide spectrum of histopathological patterns. What appears to be constant in all skin biopsies was the presence of prominent dilated blood vessels with a swollen endothelial layer, vessels engulfed with red blood cells, and perivascular infiltrates, consisting mainly of cytotoxic CD8+ lymphocytes and eosinophils. In 2 cases, there was diffuse coagulopathy in the cutaneous vascular plexus. In the early phases of the disease, there were numerous collections of Langerhans cells in the epidermis after being activated by the virus. The presence of urticarial lesions, chilblains, targetoid lesions (erythema multiforme-like lesions), exanthema, maculohemorrhagic rash, or chickenpox-like lesions associated with the histopathological features mentioned previously should cause clinical dermatologists to suspect the possibility of COVID-19 infection, especially in patients with fever and cough.

Chilblain-like lesions in children following suspected COVID-19 infection.

During the COVID-19 pandemic, chilblain-like lesions have been reported in mildly symptomatic children and adolescents. We present four children investigated for suspected COVID-19 infection who presented with acral skin findings and mild systemic symptoms. Histology from one case showed signs of vasculitis with evident fibrin thrombus.