Loss of Smell: Is It Seasonal Allergies or Covid-19?
Is your loss of smell seasonal allergies or Covid-19? Allergists explain the differences and offer allergy relief tips to help you cope.
What are seasonal allergies, exactly?
Is a pack of tissues and antihistamines as essential as your phone and keys? You’re not alone. About 8 percent of Americans have been diagnosed with hay fever (allergic rhinitis or seasonal allergies) in the past 12 months, according to the Centers for Disease Control and Prevention.
So why are the nose, eyes, and throat of so many of us hijacked by seasonal allergy symptoms?
“People with allergies have an overactive immune system,” explains Payel Gupta, MD, assistant clinical professor at Mt. Sinai Medical Center in New York and SUNY Downstate Medical Center.
“When their immune system detects an allergen, like pollen or dust mites, it overreacts by making antibodies called immunoglobulin E (IgE),” says Dr. Gupta, who is also a spokesperson for the American College of Allergy, Asthma, and Immunology, and the co-founder and chief medical officer for the telehealth allergy platform Cleared.
Those antibodies trigger the release of different chemicals in the body, most importantly “histamine,” which causes the common seasonal allergy symptoms, including runny nose, congestion, and itchy watery eyes.
These allergies are seasonal because the airborne pollen that causes them only circulates in the air during certain times of the year.
February through August is typically prime time for these respiratory allergies, according to Jill Poole, MD, allergist-immunologist with University of Nebraska Medical Center in Omaha, and a member of the Asthma and Allergy Foundation of America Medical Scientific Council.
Why seasonal allergies happen—and only to some people
Seasonal allergies may be common, but most people don’t seek treatment. Only one in ten Americans experience seasonal allergies serious enough to diagnose. What makes seasonal allergy sufferers different, says Dr. Poole, is often genetics.
“Genetic predispositions play a role to some degree as it is more common to develop allergies if one or both parents have a history of allergies,” she says.
But if one or even both of your parents have allergies, you might still be sniffle-free—and vice-versa; if your parents have zero allergies, you can still have them.
“Allergies can develop at any time during the lifespan. You can grow up with them and they can get better or you can develop them later in life,” Dr. Gupta says.
It’s very personal, which is what makes diagnosing seasonal allergies a challenge. However, a full medical history tracking your response during pollen season might provide clues. Allergists can also conduct skin allergy testing to confirm specific allergies, Dr. Poole adds.
If you have allergies and notice them getting worse over time, you’re not just imagining things, reports a February 2021 study in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
“For many of my patients, allergies are getting worse year after year,” Dr. Gupta says.
“Climate change is causing a rise in temperatures and CO2 levels which has been shown to make pollen seasons longer and stronger every year. More pollen means more symptoms for allergy sufferers,” he explains.”
“Essentially we are seeing an early spring and late fall season. So, even people with ‘seasonal’ allergies are experiencing symptoms almost year-round,” she adds.
(Try these solutions for seasonal allergies you probably haven’t heard of yet.)
Loss of smell from allergies
But get this: “Up to 50 percent of people with allergic rhinitis can experience smell disturbance with loss of smell of up to 25 percent,” Dr. Poole says.
“This is usually caused by nasal obstruction or inflammation resulting in blocking the abilities of odor particles to reach the olfactory epithelium, which is the specialized nasal tissue inside the nasal cavity involved with smell.”
Those histamines we mentioned lead to inflammation that impacts the nerves inside the nose that help humans smell, Dr. Gupta says, “and allergies can also cause inflammation in your sinuses, the cavities in your skull, and this can cause these cavities to fill up with mucus and that can also affect your sense of smell.”
Here’s how to tell if your symptoms are allergies or another medical condition.
Loss of smell from Covid-19
There are a few key differences between smell loss that’s prompted by allergies and smell loss that’s provoked by Covid-19, Dr. Gupta says.
Follow this symptom tracker to possibly tell the difference:
Unique to Covid-19:
Unique to allergies:
Itchy, watery eyes
Itchy and runny or stuffy nose
Occurs in both:
The loss of smell from Covid-19 is also more complete than the partial loss of smell that comes with allergies, Dr. Poole adds, and Covid-19 often causes taste loss, as well.
“Having allergic inflammation is a risk factor for further loss of smell with Covid-19, so optimal treatment of allergic rhinitis inflammation is recommended,” Dr. Poole says.
How to prevent smell loss from allergies
If you think you may have seasonal allergies, a wise first step is to book an allergy test with an allergist to pinpoint what you might be allergic to and to determine if you could be a candidate for immunotherapy, Dr. Gupta suggests.
Allergy immunotherapy “coaches” the body to treat the underlying cause of environmental allergies using its own immune system. By introducing small, and increasingly larger amounts of allergens into the body, the immune system gradually learns to tolerate them better.
“These therapies target the specific allergy trigger that causes the immune system to overreact and may even reduce a person’s chances of getting new allergies,” she says.
“There are two forms of FDA-approved allergy immunotherapy (AIT): either subcutaneous immunotherapy or allergy shots, that are given in a doctor’s office or sublingual immunotherapy tablets, which are taken under the tongue at home,” she explains.
Over-the-counter medicines can also potentially tame allergy symptoms. A few options Drs. Poole and Gupta sometimes prescribe for their patients:
Steroid nasal sprays
Antihistamine nasal sprays
Antihistamine eye drops
“Knowing how and when to use these medications is very important, so if you’re not feeling better, then it may be time to see an allergy specialist,” Dr. Gupta says.
(Check out the best allergy nasal sprays that allergists recommend.)
Lifestyle medications certainly can’t hurt either. Poole recommends these allergen avoidance measures:
Close windows during peak pollen season
Limit time outside during high airborne allergen exposure times, which tend to be late morning and early afternoon
Shower, change clothes, and wash your face after being outside
Wear a face mask when outside
Try a neti pot or other nasal or sinus irrigation treatment
Quit smoking, if you do
(Learn more about what allergists do to control allergies.)
When to seek medical care
Since the Covid-19 virus is still swirling around—even at small rates among those who are vaccinated—if you notice any loss of smell, Dr. Gupta suggests getting tested for Covid-19.
If you test negative and believe your loss of smell might be due to allergies, check in with your allergist if your smell doesn’t return after a few weeks.
“Most smell loss is transient and resolved after four weeks, but the persistent loss of smell can lead to significant problems for the patient, including nutritional disturbance from lack of enjoyment of food and drink, social anxiety and depression,” Dr. Poole says.
Next, here are the foods that may help ease your allergies.
- Payel Gupta, MD, FACAAI, assistant clinical professor at both SUNY Downstate Medical Center and Mt. Sinai Medical Center in New York, a spokesperson for the American College of Allergy, Asthma and Immunology, and the co-founder and chief medical officer for the telehealth allergy platform Cleared
- Jill Poole, MD, allergist-immunologist with University of Nebraska Medical Center in Omahaand a member of the Asthma and Allergy Foundation of America Medical Scientific Council
- Centers for Disease Control and Prevention: "Allergies and Hay Fever"
- Proceedings of the National Academy of Sciences of the United States of America: "Anthropogenic Climate Change is Worsening North American Pollen Seasons"
- Food and Drug Administration: "Is Rinsing Your Sinuses With Neti Pots Safe?"