Allergy medicines containing steroids may hamper the body's response to coronavirus, a virologist says

• A virologist said there are concerns that taking allergy medication with steroids may prevent the body from fighting off the novel coronavirus, SARS-CoV-2.
• After inhaling a droplet carrying the coronavirus, the virus enters the body, latches to a cell and begins to replicate itself until the body is flooded with viral particles.
• If people are using allergy medication with steroids, which concentrate very highly in areas where the virus develops, it might prevent the body from being able to control the replication process.
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A research scientist who studies viruses says there are concerns, as allergy season begins, that common allergy medications could hamper the body's reaction to the novel coronavirus.

"We are quite worried about the fact that if you take steroids at a significant enough level it's going to interfere with your ability to control the viral replication during the first week," said Columbia University associate research scientist Daniel Griffin on the science-focused podcast This Week in Virology. "So we're really trying to say: 'Think this through.'"

Once it is inside the body, the coronavirus uses its spiky proteins to latch onto cell membranes, and it starts replicating itself. A virus can make 10,000 copies of itself in a matter of hours. Once the virus has hijacked enough cells, the immune system will begin to defend itself, sending white blood cells to the infected area and releasing defensive chemicals. This is when people will begin to feel seriously sick.

But Griffin's concern is that corticosteroids, present in many kinds of allergy medication, work to reduce chemicals that cause inflammation — a process which can, in turn, dampen the immune system.

In the context of coronavirus, Griffin says, there are questions among virologists about whether steroids may slow the body's counter-attack against the virus, which could give the virus a stronger advantage to develop.

It's a particularly pressing point as allergy season begins. Roughly 19.2 million US adults get hay fever, and over 50 million Americans experience various types of allergies. And, according to a 2017 Nielson survey, 75% of people turn to medication to handle their allergies.

Higher-dose steroids may make people more susceptible to flu, studies show — and the same could be true for coronavirus

"What if you use a nasal steroid, like a Flonase, Nasinex, things like those, is that really an issue?" Griffin said. "I don't know, because you can get pretty high concentrations right in the area where the virus likes to develop."

Too little is known about the novel coronavirus to discern exactly how it matches up against steroid-impacted lungs.

However, there is plenty of evidence showing influenza was more virulent in people taking high doses of steroids.

In a 2016 study patients with influenza who took over 150 milligrams a day of methylprednisolone (sold under the brand name Medrol to treat conditions including psoriasis and Crohn's) were infectious for longer and had higher mortality rates. In contrast, those taking 25–150 milligrams a day of the same drug fared no different compared to people who were not on steroids.

A 2019 study found that in every increase of 5 mg a day of prednisolone (a steroid prescribed for asthma) increased their risk of any kind of infection by 13%. "The higher the dose, the longer the duration, the more the risk to the individual," rheumatologist Jason Faller told Healthline, in an analysis of the study.

Instead of taking allergy medicines with steroids for seasonal allergies, try antihistamines or decongestants

Griffin, who is also the host of the This Week in Parasitism podcast, advised listeners to use a risk-benefit analysis to using the steroids.

For people with seasonal allergies who don't necessarily need allergy medications with steroids, like Flonase or Nasonex, try taking antihistamines like Zyrtec, Clarinex, or Claritin, or decongestants like Allegra-D or Claritin-D instead.

"We think, 'oh, it's going to be spring, it's going to be great, we'll have more sunshine, and maybe transmission will go down'," Griffin said. "But what happens when everyone starts spraying steroids up their noses and getting exposed?"

But people with asthma, who are among the groups with the highest risk of severe illness from COVID-19, need inhaled corticosteroids to reduce swelling in their airways. For them, both the Asthma and Allergy Foundation of America, as well as the American Academy of Allergy Asthma and Immunology, say steroids are not a risk.

"If you have asthma and you are sick and you're bronchospastic and wheezing that's a reason to use steroids," said critical care specialist David Hill, spokesperson for the American Lung Association.

The CDC noted that when corticosteroids had been used on MERS-CoV or influenza patients, those patients were more likely to have a longer viral replication periods and require ventilators. "Therefore, corticosteroids should be avoided unless indicated for other reasons," said the CDC.