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.