Does aeroallergen sensitivity and allergic rhinitis in children cause milder COVID-19 infection?

Background: There are conflicting data with regard to the impact of respiratory and allergic comorbidities on the course of novel coronavirus disease 2019 (COVID-19) in children. Objective: This study aimed to investigate the relationship between allergic diseases and COVID-19 severity in pediatric patients. Methods: Seventy-five pediatric patients with COVID-19 were classified according to clinical severity and evaluated in the allergy/immunology and pulmonology departments 1 to 3 months after the infection resolved. Blood was collected from the patients for a complete blood cell count and assessment of immunoglobulin and total immunoglobulin E (IgE) levels, and skin-prick tests and spirometry tests were performed. Results: A total of 75 patients ages 5-18 years were evaluated. COVID-19 was asymptomatic/mild in 44 patients and moderate/severe/critical in 31 patients. Based on allergy evaluation, allergic rhinitis was diagnosed in 19 patients (25.3%), asthma in 10 patients (13%), and atopic dermatitis in 3 patients (4%). Aeroallergen sensitivity was detected in 26 patients (34.7%). COVID-19 infection was asymptomatic/mild in 15 patients with allergic rhinitis (78.9%) and in 21 with aeroallergen sensitivity (80.8%) (p = 0.038 and p = 0.005, respectively). There was no difference in severity between the patients with and without asthma (p = 0.550). The median (interquartile range) total IgE level was significantly higher in the asymptomatic/mild group (71.8 [30.7-211.2]) (p = 0.015). There were no differences in terms of spirometry parameters. Conclusion: Aeroallergen sensitization and allergic rhinitis in children may be associated with a milder course of COVID-19. The knowledge that atopy is associated with less-severe COVID-19 outcomes in children may guide clinical risk classification.

Management of Allergic Diseases During COVID-19 Outbreak.

PURPOSE OF REVIEW: The coronavirus disease 2019 (COVID-19) has challenged healthcare system capacities and safety for health care workers, reshaping doctor-patient interaction favoring e-Health or telemedicine. The pandemic situation may make difficult to prioritize patients with allergies diseases (AD), face-to-face evaluation, and moreover concern about the possible COVID-19 diagnosis, since COVID-19 shared many symptoms in common with AD. Being COVID-19 a novel disease, everyone is susceptible; there are some advances on vaccine and specific treatment. We evaluate existing literature on allergic diseases (AD): allergic rhinitis, asthma, food allergy, drug allergy, and skin allergy, and potential underlying mechanisms for any interrelationship between AD and COVID-19. RECENT FINDINGS: There is inconclusive and controversial evidence of the association between AD and the risk of adverse clinical outcomes of COVID-19. AD patients should minimize hospital and face-to-face visits, and those who have used biologics and allergen immunotherapy should continue the treatment. It is essential to wear personal protective equipment for the protection of health care workers. Social distancing, rational use of facemasks, eye protection, and hand disinfection for health care workers and patients deserve further attention and promotion. Teleconsultation during COVID-19 times for AD patients is very encouraging and telemedicine platform can provide a reliable service in patient care.

Coronavirus disease 2019 and asthma, allergic rhinitis: molecular mechanisms and host-environmental interactions.

PURPOSE OF REVIEW: Coronavirus disease 2019 (COVID-19), a respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), is a pandemic in over 120 countries worldwide. Risk factors for severe COVID-19 include older age, ethnicity, sex, comorbidities, and living conditions. Although asthmatics and those with allergies are susceptible to more severe outcomes to viral infections, interestingly, asthma has not been reported to be a major comorbidity of COVID-19. However, there are some conflicting reports on the impact of asthma on COVID-19. The underlying immunological and molecular mechanisms may explain at least in part these observations. Furthermore, environmental factors like air pollution that have detrimental effects on asthma and respiratory illnesses also have an impact on COVID-19. RECENT FINDINGS: Angiotensin-converting enzyme 2 (ACE2) is the receptor for the attachment and entry of SARS-CoV-2 into the host cells that is upregulated by Th1-mediated responses. In asthmatics, ACE2 gene expression is generally reduced and recent studies have shown a negative correlation between the levels of Th2 cytokines including IL-4, IL-5, and IL-13 in airway epithelial cells and other type 2 biomarkers with ACE2 expression. This may explain in part the potential protective role of asthma on COVID-19. Here, we review the relation of respiratory viral illnesses and asthma, the immune-molecular mechanisms of SARS-CoV-2 infection, the impact of asthma on COVID-19 and that of SARS-CoV-2 on asthma and allergic rhinitis, and the impact of environmental factors like air pollution on COVID-19. SUMMARY: Expression of ACE2 in airway epithelial cells in SARS-COV-2 is influenced by inflammatory profile. Respiratory allergic diseases like asthma appear to have a protective effect against SARS-COV-2 infection. However, the clinical association between asthma and SARS-COV-2 is not fully established and the underlying immune-molecular mechanisms may explain these observations.

Allergic disorders and susceptibility to and severity of COVID-19: A nationwide cohort study.

BACKGROUND: There is inconclusive and controversial evidence of the association between allergic diseases and the risk of adverse clinical outcomes of coronavirus disease 2019 (COVID-19). OBJECTIVE: We sought to determine the association of allergic disorders with the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and with clinical outcomes of COVID-19 (admission to intensive care unit, administration of invasive ventilation, and death). METHODS: A propensity-score-matched nationwide cohort study was performed in South Korea. Data obtained from the Health Insurance Review & Assessment Service of Korea from all adult patients (age, >20 years) who were tested for SARS-CoV-2 in South Korea between January 1, 2020, and May 15, 2020, were analyzed. The association of SARS-CoV-2 test positivity and allergic diseases in the entire cohort (n = 219,959) and the difference in clinical outcomes of COVID-19 were evaluated in patients with allergic diseases and SARS-CoV-2 positivity (n = 7,340). RESULTS: In the entire cohort, patients who underwent SARS-CoV-2 testing were evaluated to ascertain whether asthma and allergic rhinitis were associated with an increased likelihood of SARS-CoV-2 test positivity. After propensity score matching, we found that asthma and allergic rhinitis were associated with worse clinical outcomes of COVID-19 in patients with SARS-CoV-2 test positivity. Patients with nonallergic asthma had a greater risk of SARS-CoV-2 test positivity and worse clinical outcomes of COVID-19 than patients with allergic asthma. CONCLUSIONS: In a Korean nationwide cohort, allergic rhinitis and asthma, especially nonallergic asthma, confers a greater risk of susceptibility to SARS-CoV-2 infection and severe clinical outcomes of COVID-19.