Don't confuse Covid-19 with hay fever, poisonous caterpillar reactions: Doctors

Electron microscope image of SARS-CoV-2, also known as the 2019-nCoV or novel coronavirus
Electron microscope image of SARS-CoV-2, also known as the 2019-nCoV or novel coronavirus. February 14, 2020NIAID-RMLFlickrCC-BY

With spring firmly in the air, and summer on the way, more people will begin to suffer from the effects of their seasonal allergies. But with coronavirus still very prevalent in the Netherlands, as well as the Covid-19 disease it causes, how does one know if they have symptoms of the serious illness, like a stuffy nose, headache or shortness of breath, or instead are suffering from either hay fever, or even a reaction to the processionary caterpillars that began hatching last week?

Several experts tell NL Times that indeed the best thing someone can do is to treat their allergies, and take steps to prevent the symptoms from showing up.

Indeed, the symptoms of hay fever and respiratory illness Covid-19 can overlap, says pulmonology researcher Dr. Letty de Weger. The pollen and seasonal allergies expert has spent the better part of the last two decades at the Leiden University Medical Center, and is the General Secretary of the European Aerobiology Society.

“At the moment there is a lot of birch pollen in the air and this pollen can cause hay fever complaints in people who are sensitive to it,” she tells NL Times. “The main symptoms of hay fever are: itchy or scratchy nose and nasopharynx, sneezing, stuffy nose, watery eyes [sometimes made worse by light],, and sometimes shortness of breath,” she continues.

“Some of these can also be symptoms of Covid-19,” she says.

“Treat the hay fever well, with corticosteroid nasal spray, so that you have as few complaints as possible and are not confused with a COVID-19 patient,” says Dr. Wytske Fokkens of the Amsterdam University Medical Center. Even before symptoms arise, closing windows and doors is a good way to ensure that the allergens do not find a way into one's home, the ear, nose, and throat doctor says.

Fokkens has an expertise in hay fever and inflammation of the sinuses, and has been a professor at the Academic Medical Center in Amsterdam since 2002. She says there are a few more simple, preventive actions people can take to keep some seasonal allergy symptoms at bay, like cleaning furniture with a cloth, drying the laundry indoors instead of outdoors, and regularly cleaning the floors with a vacuum that has a good air filter.

It would also be wise to avoid floral bouquets, flowering plants and catkins, Fokkens recommends. And if one must air out their house, they should do it “in the morning or at night, or after it rains, because then there is less pollen in the air.”

With the re-emergence of the oak processionary caterpillars last week, people might find themselves with asthma symptoms, like shortness of breath, if they interact with the toxic hairs the insects shed as a defense mechanism. But the caterpillars are more commonly associated with an itchy skin rash, and red, itchy eyes.

The itchiness is the clearest way to differentiate between a reaction to the caterpillars and a coronavirus infection, Fokkens says. Being itchy is simply not a symptom of any coronavirus-related illnesses, and by staying indoors people can avoid the reaction altogether.

Listening to the government’s advice by staying home as much as possible is one of the easiest ways to avoid hay fever and allergic reactions to bugs and insects, suggests allergist Dr. Theo Roovers from the Elisabeth-TweeSteden Ziekenhuis. Sticking to an isolation period when someone has a seasonal allergy should clear up any confusion.

“If you have stayed in your home the whole time, and you are showing symptoms, then it is normal to consider that it could be the coronavirus,” Roovers says.

Ultimately, when the signs of seasonal allergies do emerge, De Weger from LUMC recommends that hay fever sufferers continue taking whatever medicine they have effectively used to alleviate symptoms in the past. She says anyone with concerns about their symptoms should contact their general practitioner, as their family doctor should already know their medical history.