THURSDAY, Aug. 27, 2020 (HealthDay News) -- After stay-at-home orders were issued this spring because of COVID-19, doctors at Children's Hospital of Philadelphia noticed a dramatic drop in the number of patients who were being admitted for asthma emergencies or seeing their doctors for outpatient visits.
In a new study, doctors there noted the drops were significant: the hospital and its care network witnessed a 60% decrease in daily asthma health care visits and an 83% decrease in steroid prescriptions. In-person visits, partially offset by new telehealth and phone appointments, decreased by 87% for outpatient visits and 84% for hospital visits.
"We saw less asthma events overall, severe and non-severe," said study senior author Dr. David Hill, an assistant professor of pediatrics at University of Pennsylvania, and a pediatric allergist at the hospital. "We were surprised by that."
Researchers from Children's Hospital of Philadelphia (CHOP) and the Hospital of the University of Pennsylvania reviewed both the 60 days leading up to the March 17 stay-at-home orders for their region and the 60 days after those orders began. They considered possible asthma triggers, choosing to focus on pollution and rhinovirus, a cause of the common cold. They compared rhinovirus infection data to cases from the five previous years.
"Rhinovirus has a long history of being documented as a virus that causes asthma flares and worse asthma outcomes," Hill said. "What we found is that rhinovirus infections were less after the shutdown.
"It could be the masking and the social distancing procedures that we're implementing for COVID were also helpful in limiting rhinovirus infections. I think that's likely. It could be due to the shutdown of schools and public spaces. It could just be the enhanced hygiene procedures that all of us were doing," Hill added.
The findings were published recently in the Journal of Allergy and Clinical Immunology: In Practice.
"It's important to note that this is not causality, it's association. There could be other factors involved that we didn't study. And this is specific to our region," Hill said.
Researchers considered the impact of other viruses, including influenza A and B, but found those viruses were waning by March 17. They didn't research the impact of pollen, exposure to environmental allergens at schools or whether people were more consistently using their asthma medicines.
While overall patients experienced fewer significant asthma symptoms, two specific demographic groups did not. Black patients had a 70% increase in steroid prescriptions during this time and a higher percentage of care than they had before. Study authors said this should be a focus of future studies and efforts to improve quality of patient care. Medicaid patients saw a 63% increase in steroid prescriptions.
Asthma is a chronic condition that causes narrowing of airways, resulting in chest tightness, wheezing and shortness of breath. It affects 1 in every 12 children.
Dr. Shyam Joshi is an assistant professor of medicine in the section of allergy and clinical immunology at Oregon Health & Science University in Portland. He said in his area they are seeing much fewer urgent care or acutely symptomatic pediatric patients.
In addition to other measures, spring school closures likely played a big part in reducing exposure to rhinovirus and, therefore, asthma symptoms, Joshi said.
"We know that in very young patients that acute episodes of wheezing or coughing, shortness of breath, about 80% of those times are associated with an underlying viral infection," Joshi said. "Avoiding rhinovirus is going to clearly improve these acute episodes of wheezing and difficulty breathing."
In Baltimore, Dr. Corinne Keet, an associate professor of pediatrics at Johns Hopkins University School of Medicine, said she also is seeing patients with fewer asthma exacerbations this spring and they're self-reporting improved asthma symptoms.
Though viruses can be the most immediate trigger, allergic inflammation plays a key role in asthma symptoms. When they treat that first, patients don't experience as many significant asthma symptoms, Keet said.
It's too early to say what the upcoming flu season will be like, Keet said, but consistent hand-washing and mask wearing can help.
"It's not just COVID that is reduced when we do all those things. All the respiratory viruses share those common transmission pathways," Keet said. "Hand-washing, covering our faces, being away from other people reduce all of those things."
Hill suggested a more controlled study of the benefits of wearing masks and enhanced hygiene is needed.
"If we can better understand why it is that asthma activity went down, perhaps we can emulate some of those things or, at least in select populations of severe asthmatics, institute some of those procedures to try to reduce asthma activity outside of a global pandemic," Hill said.
There's more on asthma attacks at the American College of Asthma, Allergy & Immunology.