Seasonal Allergies (Hay Fever)

Seasonal allergies, also called hay fever, are the body’s reaction to pollen in the air. They cause sneezing, a runny nose, and itchy, watery eyes. Seasonal allergies are not contagious and do not cause fever.

What Is It

In the Chicago area, tree pollen peaks in spring, grass pollen in early summer, and ragweed from August until the first frost. Mold spores rise after rain and in fall leaves. Allergies often run in families with eczema and asthma.

Symptoms

Sneezing
A runny nose with clear, watery mucus
Stuffy nose
Itchy, watery, red eyes
Itchy throat, nose, or ears
Postnasal drip and cough

Not sure it’s allergies? A cold brings body aches and sometimes fever, and clears in about a week. Allergies cause itching and last as long as the pollen does. Face pressure and thick mucus may be a sinus infection.

Treatment

At your visit: A provider confirms the symptoms are allergies and checks for a sinus infection, ear fluid, or an asthma flare. Treatment may include antihistamines, nasal sprays, and eye drops. Hard to control allergies may need allergy testing.

At home:

Start allergy medicine 2 weeks before your usual season
Use a steroid nasal spray daily during the season
Keep windows closed and run the air conditioning on high pollen days
Shower and change clothes after time outdoors

Symptoms ease once the pollen season ends, or with steady daily treatment.

When to Get Care for Seasonal Allergies

Watch at Home

Sneezing and runny nose controlled by over the counter medicine
No fever
Sleeping well

Come to Urgent Care Today

Symptoms not controlled by over the counter medicine
Face pressure, thick mucus, or symptoms lasting over 10 days
Ear pain or fullness with allergy symptoms
Wheezing or coughing at night during allergy season
Allergies that keep you from sleeping, work, or school

Go to the Emergency Department

Trouble breathing or wheezing that does not ease with your inhaler
Swelling of the lips, tongue, or throat
Hives across the body with dizziness or vomiting

FAQ

How do I know if it is allergies or a cold?

Allergies cause itchy eyes and nose, clear mucus, and no fever, and they last as long as the pollen season. A cold brings body aches and clears in about a week.

When is allergy season in Illinois?

Allergy season in Illinois runs from spring tree pollen through summer grass pollen and fall ragweed, which lasts until the first frost.

Can seasonal allergies cause a fever?

No, seasonal allergies do not cause a fever. A fever points to an infection, like a cold, flu, or sinus infection.

What is the best treatment for seasonal allergies?

The best treatment for seasonal allergies is a daily steroid nasal spray, often with an antihistamine. Starting 2 weeks before the season helps most.

Can urgent care treat allergies?

Yes, urgent care can treat seasonal allergies. At Vitality Urgent Care, a provider can check for sinus infections and asthma flares. No appointment or referral is needed.

Can allergies cause a sinus infection?

Yes, allergies can swell the sinuses and block drainage, which can lead to a sinus infection. Symptoms lasting over 10 days should be checked.

Last reviewed October 2026