Yes, You Can Have Allergies in Winter

It’s respiratory illness season. Your nose is stuffed or running, you’re coughing and sneezing, and everyone around you is taking a step back. You’re wondering if you might have a cold, influenza (the flu), respiratory syncytial virus (RSV), or COVID-19. But could it be something else?

“If nasal congestion does not go away after a week or two, you might have allergies, not cold or flu, especially if eyes are itchy or watery,” says Columbia allergist Joel Brooks, DO.  

It’s important to be tested for COVID, RSV, and the flu. But if viruses have been ruled out as the cause of your symptoms, it’s time to consider allergies, which are an immune response to a trigger.

Dr. Brooks explains the possible causes of allergies in winter and how to get relief.  

Which allergens are present in winter?

Winter is cold and virus season, but you can still have allergies at any time.

Most winter allergens—substances that induce allergic responses—are found indoors. Dust mites, pet dander, mice, cockroaches, and mold are frequent triggers of allergy symptoms, like sneezing, itching, skin rashes, and trouble breathing, during winter months.

Why are environmental allergens worse in winter, when they’re present year-round?

There are a few reasons. These allergens are more problematic during the colder months because we tend to spend more time indoors. With most homes sealed tightly to conserve heat, ventilation is limited, and allergens can get trapped inside, reducing air quality. Heated air systems also stir up dust and other particles that may have settled. In addition, the cold, damp conditions of winter can promote mold growth, making indoor allergens even more challenging. During winter, we also wear more clothing, which can trap dust and allergens.

To help reduce indoor allergens, consider using air purifiers, controlling humidity levels, and cleaning regularly.

Who is susceptible to winter allergies?

Everyone. Environmental allergies (immune reactions to allergens in your surroundings) can happen in children and adults, although they are rare in children below age three.

How do I know if I have allergies, not cold, flu, COVID, or other illnesses?

When it comes to respiratory illness and reactions, there are many symptoms common to both environmental allergies and infections, including cough, nasal congestion, headaches, and fatigue. But there are also several key differences.

• Fevers, chills, muscle and body aches, loss of taste and smell, nausea, vomiting, and diarrhea are commonly seen in viral infections and are rarely seen in environmental allergies.
• Itchy or watery eyes and sneezing are commonly seen in environmental allergies.

The NIH and CDC have helpful resources to learn more about these differences.

What’s the most frequent question people ask about allergies, and what do you tell them?

Are environmental allergies causing my hives?

Perhaps. But viruses are a far more common cause of hives. During the winter, allergists commonly see patients who report developing hives without a clear trigger. When someone has hives, it’s important to first rule out food or environmental allergies. The next most common trigger is a virus.

Approximately 50% of children will experience an episode of hives due to a virus. Hives can develop due to viruses at any age. Some people who get hives never know they are sick because their immune system deals with the infection quickly. Any infection of any duration can still be enough to cause an outbreak of hives.

What’s the one thing you want everyone to know about allergies?

They’re treatable! If you or someone in your home is experiencing symptoms like respiratory issues, it’s important to consult a doctor. Since managing allergies differs significantly from treating infections, understanding what’s triggering the symptoms is essential. Identifying the root cause—whether it's an allergen or an infection—is key to getting the right treatment. By taking action and knowing the cause, you not only protect your own health but also help prevent potential reactions in others. Early detection and proper treatment can make all the difference in living comfortably and safely.