Seasonal Allergy

Hay fever, Allergic rhinitis

Seasonal allergies affect millions of people, turning beautiful spring days and sunny summers into times of sneezing, itchy eyes, and congestion. When trees bloom and grasses grow, your body may mistake harmless pollen for a dangerous invader, causing uncomfortable symptoms that can last for weeks or months.

Table of contents

• What are seasonal allergies?
• Common symptoms
• Common triggers and when they occur
• How seasonal allergies are diagnosed
• Reducing your exposure to allergens
• Treatment options
• Impact of climate change on allergy seasons

What are seasonal allergies?

Seasonal allergies develop when the body’s immune system (the system that protects your body from illness) overreacts to something in the environment that is usually harmless^[1]. During spring, summer, or fall, certain plants release tiny particles called pollen into the air as part of their reproduction process. When you breathe in this pollen, your body may treat it as a dangerous invader, even though it is completely harmless to most people^[2].

Your immune system responds by releasing chemicals such as histamines (substances that cause inflammation and allergic symptoms) into your bloodstream to fight off what it thinks is a threat^[5]. This reaction causes the uncomfortable symptoms that make you feel miserable during certain times of the year. The severity of your symptoms depends on which pollens you are allergic to, how much pollen is in the air, and how much contact you have with it^[5].

More than one in four adults and one in five children in the United States have seasonal allergies^[11]. This condition is also known as hay fever or allergic rhinitis. Around 50 million Americans suffer from allergies each year^[2].

Common symptoms

Seasonal allergy symptoms typically appear suddenly and can last from a few days to several months, depending on how long you are exposed to the allergen^[5]. The most common symptoms include^[2][6]:

• Sneezing
• Runny or stuffy nose
• Congestion
• Itchy eyes, nose, and throat
• Watery, red eyes
• Coughing
• Post-nasal drip (mucus that runs down the back of your throat)
• Fatigue or tiredness

Unlike colds, seasonal allergies usually last longer than a week or two^[4]. If you blow your nose and the discharge is clear, it is usually a sign of allergies rather than a cold. Allergies do not cause fever, while viral infections often do^[13]. One aspect of allergies that many people don’t realize is that they can make you feel really tired or fatigued, which can affect your daily activities and concentration^[2].

For some people, seasonal allergies can trigger or worsen asthma symptoms, leading to difficulty breathing, wheezing, and persistent coughing^[4][11]. Many people with seasonal allergies also have asthma, and pollen can trigger asthma attacks^[4].

Common triggers and when they occur

The timing of seasonal allergies depends on where you live and what you are allergic to. In many areas of the United States, spring allergies begin in February and last until early summer. Tree pollen appears first, followed by grass pollen later in the spring and summer, and ragweed in late summer and fall^[1].

Different plants release pollen at different times throughout the year^[2][4]:

• Spring allergies: Tree pollen from birches, oaks, elms, maples, cedar, and pine is most common. This typically occurs from March through April, though it can start as early as February in some regions.
• Summer allergies: Grass pollen becomes the main problem from late spring through early summer, usually peaking in June and July.
• Fall allergies: Ragweed is the most common culprit. Ragweed blooms and releases pollen from August to November, with levels often highest in early to mid-September.
• Year-round concerns: Mold spores can cause seasonal allergies during spring, summer, and fall, especially in areas with high humidity.

In tropical climates, grass may pollinate throughout much of the year^[1]. Mild winter temperatures can cause plants to pollinate earlier than expected, and a rainy spring can promote rapid plant growth, leading to increased mold and symptoms that last longer into the fall^[1].

Several climate factors influence how bad your symptoms might be. Tree, grass, and ragweed pollens thrive during cool nights and warm days. Molds grow quickly in heat and high humidity. Pollen levels tend to peak in the morning hours, and rain washes pollen away temporarily, but pollen counts can surge after rainfall. On calm days with no wind, pollen stays close to the ground, but when the day is windy and warm, pollen counts can soar^[1].

How seasonal allergies are diagnosed

If you experience symptoms only at certain times of the year, you may have a seasonal allergy. If you feel like you are always getting sick with cough or congestion, or if your symptoms are affecting your daily life, it is time to see a doctor or allergist^[1].

A healthcare provider can diagnose allergies through testing. Understanding exactly what causes your allergies can help you prevent exposure and treat your reactions more effectively^[4]. There are two main types of allergy tests^[2]:

Skin tests: The doctor pricks the surface of your skin, usually on the upper arm or back, and injects a tiny amount of suspected allergens. If you have an allergy, the skin will react by becoming inflamed, red, and swollen, which may cause temporary discomfort. Skin tests give fast results, usually within half an hour or 24 to 48 hours^[2].

Blood tests: Blood is drawn and sent to a laboratory for analysis. The disadvantage is that it may take several days for results to come back. However, more allergens can be tested with blood tests than with skin tests. Blood tests are used to identify seasonal allergies as well as year-round allergies. If you have chronic skin conditions such as psoriasis or eczema, blood tests are recommended instead of skin tests to prevent further irritation^[2].

It is important to tell your doctor about any medications you are taking, because some can affect your test results^[2]. More than two-thirds of spring allergy sufferers actually have year-round symptoms, so testing can reveal that other substances besides pollen may be involved in your suffering^[1].

Reducing your exposure to allergens

While you cannot completely avoid the outdoors, you can take steps to minimize your exposure to the pollens that trigger your symptoms. The best way to manage seasonal allergies is to reduce contact with allergens^[5][3]:

Monitor pollen counts: Check daily pollen forecasts on local TV, radio, newspapers, or the internet. When pollen counts are high, stay indoors as much as possible, especially during peak times. Pollen levels tend to be highest in the early morning and on dry, windy days. The best time to go outside is after a good rain, which helps clear pollen from the air^[3][1].

Keep windows and doors closed: During allergy season, keep windows and doors shut at home and in your car, especially at night or when pollen counts are high. Use air conditioning instead of opening windows. This prevents pollen from entering your living spaces^[3][1].

Clean yourself and your belongings: After spending time outdoors, take a shower and wash your hair to rinse pollen from your skin and hair. Change into clean clothes before going to bed, so you do not bring pollen into your bedroom. Do not hang laundry outside to dry, as pollen can stick to sheets and towels^[3][1].

Protect yourself during outdoor activities: Avoid lawn mowing, weed pulling, and other gardening chores that stir up allergens. If you must do outdoor work, wear a face mask with a filter, such as a NIOSH-rated 95 mask. Wearing wraparound sunglasses can help keep pollen out of your eyes^[1][4].

Keep your home clean: Change the filters in your heating and air conditioning systems regularly, especially during peak allergy months. Consider using filters with a MERV rating of 11 or 12 for better allergen control. Use air purifiers with HEPA filters in key rooms such as the bedroom^[11][20].

Care for your pets: If you have pets that go outdoors, brush them off or bathe them regularly, as they can carry pollen in their fur and bring it into your house^[1][5].

Treatment options

There are several ways to treat seasonal allergies, ranging from simple self-care measures to prescription medications and long-term therapies. The management of allergic rhinitis includes three major approaches: avoiding allergens, using medications, and considering immunotherapy^[6].

Over-the-counter medications: Several types of non-prescription medications can help ease symptoms^[11][22]:

• Antihistamines: These medications help relieve sneezing, stuffy or runny nose, and itchy, watery eyes. Common examples include cetirizine, fexofenadine, and loratadine. Use them daily for best results.
• Nasal corticosteroid sprays: These sprays help prevent seasonal allergy symptoms when used daily. A common example is fluticasone propionate. Nasal sprays are often most effective for people with seasonal allergies.
• Antihistamine nasal sprays: Use these as needed to relieve congestion, runny nose, and sneezing. The most common example is azelastine.
• Decongestants: These may provide temporary relief from nasal stuffiness. They come in pills or nasal sprays, but should not be used for more than a few days.

Some allergy medicines can cause side effects like drowsiness and are generally not recommended for daily use. Read labels carefully and talk with a pharmacist or healthcare provider about which type of medication is right for you^[11].

Saline nasal rinses: Rinsing your nasal passages with saline solution once or twice a day can help rinse pollen out of your nose, thin out secretions, and allow medicated nasal sprays to work better^[11].

When to start medication: Taking medication before allergy season starts and before your symptoms appear can help your body build up a defense when pollen levels rise, making it easier to control symptoms. If high pollen counts are forecasted, start taking allergy medications before your symptoms begin^[3][13].

Prescription treatments: If over-the-counter medications do not provide enough relief, your doctor can prescribe stronger medications or recommend other treatment options^[1].

Immunotherapy: For people with severe or persistent allergies, immunotherapy may be recommended. This treatment addresses the body’s immune response to allergens. Allergy shots (also called allergen immunotherapy) involve regular injections over time that gradually help your body become less sensitive to specific allergens. This treatment is useful not only because it helps with symptoms, but because it actually makes you less allergic over time^[1][16].

Impact of climate change on allergy seasons

Climate change is making allergy seasons worse. The primary cause of climate change is a rise in carbon dioxide in the atmosphere from burning fossil fuels. Carbon dioxide and other greenhouse gases trap heat, leading to increasing temperatures and global warming^[24].

Global warming is affecting the way plants grow and produce pollen. Plants like ragweed and grass now have longer growing seasons, produce higher amounts of pollen, and are growing in new geographic locations. Research has found that nationwide pollen levels increased up to 21% between 1990 and 2018^[24].

Warmer temperatures linked to climate change are extending pollen seasons, allowing plants to pollinate earlier and longer^[4]. This means that allergy season is starting earlier each year, lasting longer, and covering us with more pollen^[24].

These changes pose several problems. Increased pollen levels might worsen outdoor air quality and cause new or more intense seasonal allergy symptoms. It can also be harder to predict when allergies might flare up and when to begin taking preventive medications. The longer and more unpredictable allergy seasons mean you may need to take more precautions and be prepared to manage symptoms for extended periods^[24].