Synthesis of the Data on COVID-19 Skin Manifestations: Underlying Mechanisms and Potential Outcomes

COVID-19 and Its Impact on Common Diseases in the Allergy Clinics

Coronavirus disease 2019 (COVID-19) is a highly contagious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has various effects on asthma, allergic rhinitis, atopic dermatitis, and urticaria and may change the course of the disease depending on the severity of the infection and control status of the disease. Conversely, these diseases may also impact the course of COVID-19. Patients with chronic urticaria and atopic dermatitis may have COVID-19-induced disease exacerbations and biological treatments reduce the risk of exacerbations. Poor asthma control is linked to severe COVID-19 while allergic asthma is associated with lower risk of death and a lower rate of hospitalization due to COVID-19 compared with nonallergic asthma. The use of intranasal corticosteroids is associated with lower rates of hospitalization due to COVID-19 in patients with allergic rhinitis, whereas the effect of inhaled corticosteroids is confounded by asthma severity. These observations reinforce the importance of keeping allergic diseases under control during pandemics. The use of biologicals during COVID-19 is generally regarded as safe, but more evidence is needed. The pandemic substantially changed the management of allergic disorders such as home implementation of various biologicals, allergen immunotherapy, food introduction, and increased use of telemedicine and even home management of anaphylaxis to reduce emergency department burden and reduce risk of infection. Physicians need to be aware of the potential impact of COVID-19 on allergic diseases and educate their patients on the importance of continuing prescribed medications and adhering to their treatment plans to maintain optimal control of their disease.

How Infection and Vaccination Are Linked to Acute and Chronic Urticaria: A Special Focus on COVID-19

Since more than a century ago, there has been awareness of the connection between viral infections and the onset and exacerbation of urticaria. Our knowledge about the role of viral infection and vaccination in acute and chronic urticaria improved as a result of the COVID-19 pandemic but it has also highlighted knowledge gaps. Viral infections, especially respiratory tract infections like COVID-19, can trigger the onset of acute urticaria (AU) and the exacerbation of chronic urticaria (CU). Less frequently, vaccination against viruses including SARS-CoV-2 can also lead to new onset urticaria as well as worsening of CU in minority. Here, with a particular focus on COVID-19, we review what is known about the role of viral infections and vaccinations as triggers and causes of acute and chronic urticaria. We also discuss possible mechanistic pathways and outline the unmet needs in our knowledge. Although the underlying mechanisms are not clearly understood, it is believed that viral signals, medications, and stress can activate skin mast cells (MCs). Further studies are needed to fully understand the relevance of viral infections and vaccinations in acute and chronic urticaria and to better clarify causal pathways.

COVID-19 and Related Vaccinations in Children: Pathogenic Aspects of Oral Lesions

Various clinical manifestations of SARS-CoV-2 infections and adverse reactions to COVID-19 vaccination have been described in children. The present narrative review aimed to collect and synthesize reported findings on oral lesions detected in SARS-CoV-2-positive subjects following COVID-19 EMA-authorized and WHO Emergency Use Listing-approved vaccine administration in the pediatric population to detail their clinical features and highlight possible pathogenic aspects of those lesions based on current evidence. Few and incomplete reports were retrieved from the literature, probably because most lesions belonged to a broad spectrum of systemic diseases and syndromes and were nonspecific or inaccurately described. The most common oral lesions in pediatric SARS-CoV-2-positive patients were erosive-ulcerative lesions and macules/petechiae, primarily erythematous. In the context of COVID-19 vaccination, oral adverse reactions were rare and typically presented as erosive-ulcerative lesions, with EM-like or unspecified patterns. Future studies should investigate oral lesions in SARS-CoV-2-positive subjects and after COVID-19 vaccination in the pediatric population, taking into account viral variants and newly developed vaccines. Deeper insight into oral lesions detectable in pediatric SARS-CoV-2-positive subjects and after COVID-19 vaccination may increase clinicians' ability to improve multidisciplinary pediatric oral and general care.

The COVID-19 Pandemic: SARS-CoV-2 Structure, Infection, Transmission, Symptomology, and Variants of Concern

Since it was first detected in December 2019, the COVID-19 pandemic has spread across the world and affected virtually every country and territory. The pathogen driving this pandemic is SARS-CoV-2, a positive-sense single-stranded RNA virus which is primarily transmissible though the air and can cause mild to severe respiratory infections in humans. Within the first year of the pandemic, the situation worsened with the emergence of several SARS-CoV-2 variants. Some of these were observed to be more virulent with varying capacities to escape the existing vaccines and were, therefore, denoted as variants of concern. This chapter provides a general overview of the course of the COVID-19 pandemic up to April 2022 with a focus on the structure, infection, transmission, and symptomology of the SARS-CoV-2 virus. The main objectives were to investigate the effects of the variants of concern on the trajectory of the virus and to highlight a potential pathway for coping with the current and future pandemics.

COVID-19 detection using a model of photoplethysmography (PPG) signals

OBJECTIVE

Coronavirus disease 2019 (COVID-19) targets several tissues of the human body; among these, a serious impact has been observed in the microvascular system. The aim of this study was to verify the presence of photoplethysmographic (PPG) signal modifications in patients affected by COVID-19 at different levels of severity.

APPROACH

The photoplethysmographic signal was evaluated in 93 patients with COVID-19 of different severity (46: grade 1; 47: grade 2) and in 50 healthy control subjects. A pre-processing step removes the long-term trend and segments of each pulsation in the input signal. Each pulse is approximated with a model generated from a multi-exponential curve, and a Least Squares fitting algorithm determines the optimal model parameters. Using the parameters of the mathematical model, three different classifiers (Bayesian, SVM and KNN) were trained and tested to discriminate among healthy controls and patients with COVID, stratified according to the severity of the disease. Results are validated with the leave-one-subject-out validation method.

MAIN RESULTS

Results indicate that the fitting procedure obtains a very high determination coefficient (above 99% in both controls and pathological subjects). The proposed Bayesian classifier obtains promising results, given the size of the dataset, and variable depending on the classification strategy. The optimal classification strategy corresponds to 79% of accuracy, with 90% of specificity and 67% of sensibility.

SIGNIFICANCE

The proposed approach opens the possibility of introducing a low cost and non-invasive screening procedure for the fast detection of COVID-19 disease, as well as a promising monitoring tool for hospitalized patients, with the purpose of stratifying the severity of the disease.

Smoking increases the risk of post-acute COVID-19 syndrome: Results from a French community-based survey

INTRODUCTION

METHODS

RESULTS

CONCLUSIONS

Insights into urticaria in pediatric and adult populations and its management with fexofenadine hydrochloride

OBJECTIVE

The present narrative review provides a comprehensive update of the current knowledge on urticaria, both in adult and pediatric populations, and on the safety and efficacy of fexofenadine hydrochloride (HCl) as a treatment option.

DATA SOURCE

A literature search was conducted on Embase and Medline.

STUDY SELECTION

Clinical studies published in English and published between 1999 and 2020 were selected.

RESULTS

Although the exact pathogenesis of urticaria is not fully understood, multiple pathways of mast cell activation are discussed to explain the existence of phenotypically different clinical manifestations of urticaria. An overview of the worldwide prevalence of chronic urticaria, including disease burden and patient's quality of life is provided. The impact of urticaria on patient's life differs on the basis of whether its form is acute or chronic, but pharmacological approaches are most often needed to control the disabling symptoms. A summary of the current management of urticaria recommended by different guidelines across countries (Global; European; American; Australian; Asian; Japanese) is presented. Non-sedating, second-generation H₁-antihistamines are the preferred choice of treatment across several guidelines worldwide. Herein, the efficacy and safety of fexofenadine HCl, a representative second-generation H₁-antihistamine approved for the treatment of urticaria, is discussed. The occurrence of urticaria manifestations in COVID-19 patients is also briefly presented.

CONCLUSION

The burden of acute and chronic urticaria is high for patients. Second generation anti-histamines such as fexofenadine HCl can help managing the symptoms.

Skin manifestations in patients with coronavirus disease 2019

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) is a well established respiratory tract illness. Recent studies in adults and children have shown an increasing number of patients reporting polymorphic cutaneous manifestations during COVID-19, including different types of rashes, from maculopapular, vascular, vesicular to atypical forms.

RECENT FINDINGS

Although pathogenesis of skin manifestations is still not fully understood, it has been proposed that cutaneous involvement during COVID-19 may be the results of the activation of the immune response against severe acute respiratory syndrome coronavirus-2, the reactivation or co-infection of herpesviruses or drug hypersensitivity.

SUMMARY

According to available literature, skin manifestations in patients with COVID-19 may be categorized on the basis of their clinical presentations as follows: erythematous rashes, lesions of vascular origin, vesicular rash, urticarial rash and acute generalized exanthematous pustulosis (AGEP), erythema multiforme and other polymorphic erythema/atypical reactions. Prompt recognition of these cutaneous manifestations represents a crucial point to facilitate diagnosis and management of COVID-19 patients.

Top 10 acral skin manifestations associated with COVID-19: A scoping review

COVID‐19‐associated cutaneous manifestations are one of the most important and relatively common extra‐respiratory presentations of SARS‐COV‐2 infection. The exact identification and classification of these lesions can facilitate the accurate diagnosis and treatment. There are several case reports and small case series which describe cutaneous lesions in hands and feet. Currently, there is no scoping review about acral skin manifestations associated with COVID‐19. This paper covers the COVID‐related acral skin manifestations in 10 entities including acral papulo‐vesicular eruption, acral urticarial lesion, acral non‐inflammatory purpura and necrosis, acro‐ischemia associated COVID‐19, acral vasculitis, chilblain‐like lesion (COVID Toe), acral erythema multiform (EM) like lesion, hand and foot skin lesions associated with multisystem inflammatory syndrome in children (MISC), acral peeling conditions and red half‐moon nail sign. Future studies should focus on exact investigation of etiologies of these lesions including role of immune senescence, environment, gender, immunogenetics and relation of these lesion with major organ involvements.