COVID-19 infection associated with 6 months of poor asthma control in children

Children with asthma had worse outcomes in the 6 months following SARS-CoV-2 infection confirmed by a polymerase chain reaction test, according to a study published in The Journal of Allergy and Clinical Immunology: In Practice.

Christine C. Chou, MD, pediatrician at Children’s Hospital of Orange County Breathmobile asthma clinic, and colleagues called their study the first large-scale nationwide research demonstrating these effects.

Previously, the researchers reported a dramatic reduction in asthma morbidity after the middle of March 2020 when compared with earlier years, with multiple hypotheses explaining and additional studies validating this effect.

The current study evaluated the records of 61,916 children with asthma aged 2 to 17.9 years in the Cerner Real-World Data who had received a SARS-CoV-2 polymerase chain reaction (PCR) test between March 2020 and February 2021.

The researchers measured these patients’ asthma control via oral corticosteroid (OCS) fills, ED use, hospitalization and short-acting beta agonist (SABA) filling rates per 1,000 patients each 6 months.

Children with negative SARS-CoV-2 tests had significant reductions in asthma-related hospitalizations, ED visits, OCS fill rates and SABA use in the 6 months after their test compared with the 6 months before the test (P < .001).

The children who had positive SARS-CoV-2 tests experienced significant increases in ED visits (incidence rate ratio [IRR] = 1.17; P = .018) and OCS fills (IRR = 1.23; P < .001) as well as slight increases in hospitalizations (IRR = 1.13) and SABA use (IRR = 1.02) in the 6 months following their infections compared with their prior history.

In the 6 months before the PCR tests, there were no significant differences in ED, hospitalization or SABA fill rates for children who tested positive or negative for SARS-CoV-2, although the children with positive tests had slightly lower OCS fill rates than those with negative tests (IRR = 0.88; P = .002).

During the 6 months that followed testing, the children who tested positive for SARS-CoV-2 had significantly higher ED rates (IRR = 1.73; P < .001), hospitalization rates (IRR = 4.81; P < .001), OCS fill rates (IRR = 1.5; P < .001) and SABA fill rates (IRR = 1.66; P < .001) compared with those who tested negative.

Hygiene and public health measures, in addition to decreased exposures to particulate matter and viral triggers, may have led to overall improvements in asthma control during the COVID-19 pandemic, the researchers suggested.

But this overall decrease in asthma exacerbations during the pandemic’s lockdown, when there were fewer asthma triggers in the community, likely masked how SARS-CoV-2 can trigger asthma, the researchers continued.

Further, the researchers attributed the apparent protective effect that high-risk asthma patients experienced against SARS-CoV-2 infection to increased inhaled corticosteroid use and/or atopic status due to reduced expression of angiotensin-converting enzyme-2, which is an entry receptor for the virus.