Introduction
Allergies are chronic immune-mediated diseases that have become a
worldwide public health problem[1]. An
epidemiological survey conducted by WAO revealed that 22% of total
population in more than 30 countries suffer from allergic
diseases[2]. In high-income countries, 20% of
children have atopic dermatitis[3]. In addition,
the incidence of allergic diseases has been and will continue to rise
over the next two decades[4]. For individuals,
allergic diseases can reduce the quality of life and productivity. A
study in Canada found that 48.7% of asthmatic patients recruited
experienced the drop in productivity due to
asthma[5]. Allergic diseases have caused a
tremendous socioeconomic burden as well. For example, researches have
shown the United States has spent over $960 billion annually on asthma
management[6].
COVID-19 outbreak was declared a global pandemic after the first case of
Coronavirus Disease 2019 (COVID-19) was identified in Wuhan, Hubei
Province, China, in 2019. During the pandemic, strict prevention and
control measures have been adopted worldwide, particularly in China,
among which non-pharmacological interventions (NPI), including closing
public spaces, restricting gatherings, reducing unnecessary outings and
maintaining social distancing wearing masks, and keeping hand hygiene.
These NPIs have influenced people’s living environments and lifestyles,
leading to higher indoor allergen concentrations and more time spent
indoors[7].The exposure to outdoor allergens also
rises as people travel more after the lifting of certain travel
restrictions. These are bound to bring changes in allergen
sensitization. Yet, few researches have studied the impact of COVID-19
on allergen sensitization. Understanding allergen sensitization during
the pandemic can help patients identify allergens, as well as take steps
to reduce allergen sensitization and allergic disease progression in a
period of regular epidemic prevention and control. In this study, we
analyzed the positive rates of inhaled allergen sIgE (specific antibody
immunoglobulin IgE, sIgE) before and during COVID-19 to investigate its
impact on allergy sensitization.