Allergic Rhinitis Shows Dual Effect on COVID-19 Symptoms; Sublingual Immunotherapy Alters Outcomes
Allergic rhinitis demonstrates both protective and risk associations with COVID-19 symptoms, while sublingual immunotherapy modifies respiratory and fever outcomes in patients with the condition.
A study in China assessed 1,368 participants within 1 month of adjustments to COVID-19 response measures, including 746 individuals with allergic rhinitis and 622 controls without allergic diseases. Among infected participants with allergic rhinitis, 122 received sublingual immunotherapy and 483 did not.
Allergic rhinitis demonstrated a dual effect on COVID-19 symptom patterns. Compared with non-allergic individuals, patients with allergic rhinitis had a lower likelihood of respiratory symptoms, suggesting a protective association. However, allergic rhinitis was also linked to a higher risk of olfactory and gustatory dysfunctions as well as fever. These findings indicate that allergic rhinitis may modulate immune responses in complex ways during acute viral infection.
Among patients with allergic rhinitis, sublingual immunotherapy was associated with distinct differences in COVID-19 presentation. Those receiving sublingual immunotherapy had a higher risk of respiratory symptoms compared with those not treated with immunotherapy. In contrast, the risk of fever was lower in the sublingual immunotherapy group. The therapy did not significantly influence the occurrence of olfactory or gustatory dysfunctions.
These data suggest that immunomodulatory treatment may alter specific inflammatory pathways relevant to respiratory and systemic manifestations of COVID-19.
The findings highlight important considerations for clinicians managing allergic rhinitis during periods of high COVID-19 transmission. Respiratory symptoms should be carefully evaluated when deciding whether to continue or initiate sublingual immunotherapy in patients with concurrent infection. The altered risk of fever warrants attention with regard to monitoring and clinical assessment. Further research is needed to understand the mechanisms behind these associations and to inform personalised treatment strategies for patients with allergic rhinitis.