'Stay at home': Is it good or not for house dust mite sensitized children with respiratory allergies?

Background: Lockdown was imposed for children for 75 days in Turkey to limit the spread of COVID-19. During this period, children have to stay indoors, which might probably increase their exposures to indoor allergens and pollutants. Besides, reduced exposures to respiratory tract infections and outdoor pollutants might be favorable outcomes of this lockdown period. We evaluated the effects of the lockdown on house dust mite (HDM)-sensitized children with respiratory allergies.

Methods: Three-month clinical and medication data of 165 mild-moderate asthmatic children with or without allergic rhinitis (AR), who were grouped according to their HDM sensitization status, were retrieved from patient records. Demographics, asthma control tests, nasal visual analog scores, and outdoor air quality monitoring data were used for assessments in comparisons with the same period in the previous year.

Results: Eighty-four patients had asthma, and 81 patients had asthma with AR. Sensitization to HDM was present in 61.8% of the children. Patients experienced reduced numbers of upper respiratory tract infections (P = .008) and reduced asthma exacerbations (P < .001) compared with the same period in the previous year. Asthma control tests were significantly improved (P < .001), and cumulative inhaled corticosteroid usages were significantly reduced (P < .001). Noteworthily, nasal symptoms were significantly worsened in HDM-sensitized asthmatics with AR (P < .001).

Conclusions: This study highlighted that reduction in respiratory tract infections and outdoor pollution may play roles in asthma control and prevent exacerbations despite continuous indoor allergen exposure. Besides, worsening of nasal symptoms in HDM-sensitized asthmatics with AR implies the importance of indoor avoidance measures for AR control.