To synthesize recent advances in understanding the mechanisms linking SARS-CoV-2 infection to increased incidence of allergic diseases and propose a risk assessment framework.
Approach:
Key Findings:
SARS-CoV-2 infection is associated with increased incidence of allergic diseases, with hazard ratios of 2.25 (95% CI 1.80–2.83) for asthma and 1.23 (95% CI 1.15–1.32) for allergic rhinitis.
Epithelial injury during COVID-19 triggers the release of alarmins (IL-33, TSLP, IL-25) that promote type 2 immune responses.
Regulatory T cell depletion and potential epigenetic reprogramming may lead to altered immune cell responses.
Mast cells are activated by the spike protein of SARS-CoV-2, contributing to neuroinflammation and allergic susceptibility.
Interpretation:
The mechanisms linking SARS-CoV-2 infection to allergic conditions involve complex interactions between immune responses and epithelial injury.
Limitations:
Most studies lack baseline assessments of allergic status, complicating causal inference.
Follow-up periods in cohort studies are insufficient to determine the durability of observed risk elevations.
Inter-study variability may reflect differences in population genetics and prior allergic burden.
Conclusion:
The review highlights the need for targeted surveillance for individuals at risk of developing allergic diseases post-SARS-CoV-2 infection.
