SARS-CoV-2 and Skin: New Insights and Perspectives

From Viral Infection to Skin Affliction: Unveiling Mechanisms of Cutaneous Manifestations in COVID-19 and Post-COVID Conditions

COVID-19 skin manifestations are multifaceted, ranging from urticaria, morbilliform or papulovesicular rash, livedoid purpuric lesions, and to pseudochilblains (also called COVID toes). Recent insights into the mechanism of these manifestations have highlighted that morbilliform, papulovesicular, and livedoid/purpuric rashes are related to virus-induced endothelial cell damage and linked to moderate-to-severe disease, whereas pseudochilblains are related to an exaggerated IFN-1 production by plasmacytoid dendritic cells in protected individuals. In this paper, we will review the clinical and physiopathological features of cutaneous COVID-19 manifestations in relation to the direct viral cytopathic effects and dysregulated IFN-1 responses. We will also review the emerging insights into post-COVID conditions (also termed long COVID) and how they may be implicated in the persistence of COVID-19-associated skin diseases.

Dermatological complications due to post‑COVID‑19 syndrome: A systematic review

Almost 20% of patients affected by COVID-19 develop dermatological symptoms after recovery. This condition is termed as post-COVID-19 syndrome and is characterized by a state of hyperinflammation, as well as deregulations in the humoral response of CD8+ T-cells. Since there is no specific treatment for these injuries, the treatment of choice depends on the symptoms; thus, it is essential to provide a description of the type and nature of the injuries presented. In the present study, a systemic review was performed using the PICO strategy in the repositories of PubMed, Google Scholar, Embase and Scopus using the key words 'POST-COVID and skin symptoms'. A total of 44 studies were included in the present systematic review. In these studies, the majority of subjects exhibited non-specific symptoms, commonly referred to as 'skin rash', affecting up to 27.4% of the population. According to the studies, a maximum prevalence of 50% of alopecia was observed among the affected subjects. Additionally, several studies reported the prevalence of other lesions, including pruritus (25%), subcutaneous nodules (12%), dermatitis (9.4%), edema (9%) and pigmentation changes (6%). Dermatological lesions associated with autoimmunity were also identified, with these findings being more pronounced among females and in patients with a history of severe COVID-19. Finally, several studies investigated the presence of autoantibodies, revealing a maximum prevalence of 41% for autoantibodies targeting the epidermis. Specifically, the prevalence was 12.9% for the Wuhan variant, 5.7% for the Alpha variant and 5% for the Delta variant. Although mostly benign, post-COVID-19 syndrome produces marked dermatological alterations for hair health, mainly among females. This, together with the development of lesions with an autoimmune component, constitutes an emerging therapeutic need.

The "Magnificent Seven" in Oral and Systemic Health against COVID-19

The COVID-19 pandemic impacted all areas of daily life, including medical care. Unfortunately, to date, no specific treatments have been found for the cure of this disease, and therefore, it is advisable to implement all possible strategies to prevent infection. In this context, it is important to better define the role of all behaviors, in particular nutrition, in order to establish whether these can both prevent infection and improve the outcome of the disease in patients with COVID-19. There is sufficient evidence to demonstrate that immune response can be weakened by inadequate nutrition. Nutrition management and treatment are very important to enhance the immune response of an infected person against RNA viral infection. A complete nutritional assessment should include anthropometric, dietary, and laboratorial assessment, as well as a multidisciplinary discussion about the patient's clinical condition. In this way, it is possible to establish an individualized nutritional approach to contribute to improving clinical and nutritional prognoses. From this point of view, diet, through intake of vitamins and trace elements and maintaining adequate functioning of the intestinal barrier, can reduce the severity of the COVID-19 infection. In this study, we provide an overview of the effects of diet on COVID-19 infection in non-cancer patients. This notion needs to be further evaluated, and thus, identification, characterization, and targeting of the right nutrition principles related to the management of patients with COVID-19 are likely to improve outcomes and may prevent the infection or lead to a cure.

Skin Manifestations Among Patients Admitted with COVID-19: A Cross-Sectional Study at a University-Based Tertiary Hospital in Jordan

BACKGROUND

COVID-19 pandemic hit the entire world with severe health and economic consequences. Although the infection primarily affected the respiratory system, it was soon recognized that COVID-19 has a multi-systemic component with various manifestations including cutaneous involvement.

OBJECTIVE

The main objective of this study is to assess the incidence and patterns of cutaneous manifestations among moderate-to-severe COVID-19 patients who required hospitalization and whether there was a prognostic indication for cutaneous involvement and the outcome in terms of recovery or death.

METHODS

This is a cross-sectional observational study that included inpatients who were diagnosed with a moderate or severe COVID-19 infection. The demographic and clinical data of patients were assessed including age, sex, smoking, and comorbidities. All patients were examined clinically for the presence of skin manifestations. Patients were followed for the outcome of COVID-19 infection.

RESULTS

A total of 821 patients (356 females and 465 males) aged 4-95 years were included. More than half of patients (54.6%) aged >60 years. A total of 678 patients (82.6%) had at least one comorbid condition, mostly hypertension and diabetes mellitus. Sixty-two patients (7.55%) developed rashes; 5.24% cutaneous and 2.31% oral. The rashes were then grouped into five major types: group A, Exanthema: morbilliform, papulovesicular, varicella-like. Group B, Vascular: Chilblain-like lesions, purpuric/petechial, livedoid lesions. Group C, Reactive erythemas: Urticaria, Erythema multiforme. Group D, other skin rashes including flare-up of pre-existing disease, and O for oral involvement. Most patients (70%) developed rash after admission. The most frequent skin rashes were reactive erythema (23.3%), followed by vascular (20.9%), exanthema (16.3%), and other rashes with flare-ups of pre-existing diseases (39.5%). Smoking and loss of taste were associated with the appearance of various skin rashes. However, no prognostic implications were found between cutaneous manifestations and outcome.

CONCLUSION

COVID-19 infection may present with various skin manifestations including worsening of pre-existing skin diseases.

Determinants of COVID-19 Disease Severity-Lessons from Primary and Secondary Immune Disorders including Cancer

At the beginning of the COVID-19 pandemic, patients with primary and secondary immune disorders-including patients suffering from cancer-were generally regarded as a high-risk population in terms of COVID-19 disease severity and mortality. By now, scientific evidence indicates that there is substantial heterogeneity regarding the vulnerability towards COVID-19 in patients with immune disorders. In this review, we aimed to summarize the current knowledge about the effect of coexistent immune disorders on COVID-19 disease severity and vaccination response. In this context, we also regarded cancer as a secondary immune disorder. While patients with hematological malignancies displayed lower seroconversion rates after vaccination in some studies, a majority of cancer patients' risk factors for severe COVID-19 disease were either inherent (such as metastatic or progressive disease) or comparable to the general population (age, male gender and comorbidities such as kidney or liver disease). A deeper understanding is needed to better define patient subgroups at a higher risk for severe COVID-19 disease courses. At the same time, immune disorders as functional disease models offer further insights into the role of specific immune cells and cytokines when orchestrating the immune response towards SARS-CoV-2 infection. Longitudinal serological studies are urgently needed to determine the extent and the duration of SARS-CoV-2 immunity in the general population, as well as immune-compromised and oncological patients.

Receptors and Cofactors That Contribute to SARS-CoV-2 Entry: Can Skin Be an Alternative Route of Entry?

To prevent the spread of SARS-CoV-2, all routes of entry of the virus into the host must be mapped. The skin is in contact with the external environment and thus may be an alternative route of entry to transmission via the upper respiratory tract. SARS-CoV-2 cell entry is primarily dependent on ACE2 and the proteases TMPRSS2 or cathepsin L but other cofactors and attachment receptors have been identified that may play a more important role in specific tissues such as the skin. The continued emergence of new variants may also alter the tropism of the virus. In this review, we summarize current knowledge on these receptors and cofactors, their expression profile, factors modulating their expression and their role in facilitating SARS-CoV-2 infection. We discuss their expression in the skin and their possible involvement in percutaneous infection since the presence of the virus has been detected in the skin.

Extracellular Vesicle-Based SARS-CoV-2 Vaccine

Messenger ribonucleic acid (RNA) vaccines are mainly used as SARS-CoV-2 vaccines. Despite several issues concerning storage, stability, effective period, and side effects, viral vector vaccines are widely used for the prevention and treatment of various diseases. Recently, viral vector-encapsulated extracellular vesicles (EVs) have been suggested as useful tools, owing to their safety and ability to escape from neutral antibodies. Herein, we summarize the possible cellular mechanisms underlying EV-based SARS-CoV-2 vaccines.

The Pandemic and Your Skin—Direct and Indirect Impact of COVID-19

Apart from well-known respiratory symptoms, less frequent symptoms also appear as a direct result of COVID-19 infection, or as indirect effects of the recommended quarantine and related lifestyle changes. The impact of the COVID-19 pandemic on human skin is predominantly focused on in this article. Cutaneous manifestations, including redness, chilblain-like symptoms (COVID toes), hives or urticaria rash, water blisters, and fishing net-like red-blue patterns on the skin, may appear as accompanying or as systemic COVID-19 symptoms with potential lesions at different skin sites. These symptoms were related to skin phototypes and vitamin D deficiency. Moreover, Black, Asian, and minority ethnic origin patients are found to be more sensitive to COVID-19 infection than Caucasians because of vitamin D deficiency. The region of population with lighter skin phototypes have a significantly higher chance to develop cutaneous manifestations than population with dark skin. In addition, adverse effects, such as skin barrier damage and irritation, may also occur due to extensive personal protective equipment usage (e.g., masks, protective suits, and a few others) and predominately alcohol-based sanitizers. This manuscript covers various aspects of COVID-19 and its clinical skin manifestations.

"GONE WITH THE WIND": The Transitory Effects of COVID-19 on the Gynecological System

The coronavirus disease no longer seems to represent an insurmountable global problem. This is thanks to the advent of coronavirus vaccines, which have alleviated the most serious symptoms associated with this disease. On the other hand, there are still many extrapulmonary symptoms of COVID-19, and among these also those of a gynecological nature. At the moment, there are several questions in this field, one above all concerns the causal link between COVID-19, vaccines and gynecological alterations. Furthermore, another important aspect is represented by the clinical impact of post-COVID-19 gynecological alterations on the female population which, to date, would seem to be mainly due to their duration, even if the extent of these symptoms is still poorly understood. Furthermore, it is not possible to foresee eventual long-term aggravations, or more serious symptoms caused by other viral variants that may arrive in the future. In this review, we focus on this theme and attempt to reorganize the different pieces of a puzzle which, to date, does not seem to have shown us its complete picture.

Histopathological Patterns of Cutaneous Adverse Reaction to Anti-SARS-CoV-2 Vaccines: The Integrative Role of Skin Biopsy

The advent of vaccines represented a milestone to allow the slowing down and then containing of the exponential increase in ongoing infections and deaths of COVID-19. Since the first months of the vaccination campaign in various continents, there has been a certain number of reports of adverse events, including skin reactions. We conducted a systematic review, searching on PubMed, Web of Science, Scopus, and Cochrane Library for the words: COVID vaccine, dermatopathology, skin, eruptions, rash, cutaneous, BNT162b2 (Pfizer-BioNTech), ChAdOX1 (AstraZeneca), and mRNA-1273 (Moderna). A total of 28 records were initially identified in the literature search of which two were duplicates. After screening for eligibility and inclusion criteria, 18 publications were ultimately included. Various clinical cutaneous manifestations and histopathological patterns following vaccination have been described in literature. The most frequent clinical-pathological presentations were erythematous maculo-papular eruptions in different way of distribution with histopathological pictures mostly represented by interface changes and mixed peri-vascular and peri-adnexal cell infiltrate. Other presentations included new onset of pemphigoid bullous disease (n = 15), delayed T-cell-mediated hypersensitivity reaction (injection site reactions) (n = 10), purpuric skin rash (n = 13), mostly localized on the legs bilaterally and symmetrically with histological pictures characterized by extravasation of erythrocytes in the superficial and middle dermis, and other types of reactions. New studies with large case series and further literature reviews are needed to improve the clinical management of patients and optimize the timeline for carrying out histological biopsy for confirmatory, supportive, and differential diagnosis purposes.

Effects of Vitamin D on the Renin-Angiotensin System and Acute Childhood Pneumonia

Vitamin D promotes kidney calcium reabsorption and regulates calcium and phosphate metabolism, as well as the intestinal absorption of calcium and phosphorus and bone mineralization events. Vitamin D is also known for its immunomodulatory properties. It has been shown in the literature that the active form of vitamin D, 1,25-dihydroxyvitamin D, performs multiple functions in the adaptive and innate immune system, as well as acting on the endothelial membrane. Recent evidence shows that vitamin D is a negative endocrine modulator of the renin-angiotensin system (RAS), with protection from diseases leading to lung damage, such as pneumonia caused by various pathogens. Vitamin D support associated with the use of antibiotics could be crucial to counteract these infectious diseases.