Although seasonal asthma can be bothersome, understanding common allergens and weather conditions that trigger symptoms is pertinent for preventing allergy and asthma.

Certain seasons are worse for some people with asthma, a chronic lung disease in which airways are inflamed and constricted. Seasonal asthma only flares up at certain times of the year. It may be due to seasonal allergens (normally harmless substances that trigger an immune reaction) or irritants related to the weather.

For example, if you are allergic to tree pollen (an allergen), spring may be a challenge for you because that's when trees produce pollen in large quantities. In the winter, breathing in cold, dry air can dry out and irritate your airways, causing asthmatic symptoms.

This article will discuss the common causes, symptoms, and treatments of seasonal asthma, including medications and reducing exposure to triggers.

Causes of Seasonal Asthma
Different seasons feature allergens and irritants that may trigger asthma symptoms. When you’re allergic to something, your immune system perceives the allergen as an invader (while it is usually harmless) and reacts.

Irritants related to the weather may also trigger asthma symptoms by an inflammatory reaction rather than an allergic reaction. Below is a list of common allergens and irritants and the seasons in which they're prevalent.

Pollen and Ragweed
Pollen is the grains or tiny seeds of flowering plants, trees, and grasses. It can cause allergy symptoms such as sniffling, sneezing, and watery eyes.1

Ragweed is an example of a plant whose pollen triggers allergies. It is common in the Midwest and along the East Coast of the United States. Ragweed pollen is mostly released between August and October, peaking in mid-September and continuing until the first frost kills the plant.

Mould and Mildew
Mould (fungus) can be found indoors and outdoors. Mould allergies (including mildew allergy) are triggered by inhaling spores, the tiny particles that form to reproduce mold.2 Spores can easily travel through the air. If they're breathed in, they can trigger an allergic reaction or asthmatic symptoms.

In colder climates, mould can be found in nature starting in the late winter and peaking in the late summer to early fall months (July to October). In warmer climates, the highest levels of mould spores are produced from late summer to early fall months.

Cold Weather
Cold and/or dry air outdoors can trigger narrowing of the airways, leading to asthma symptoms. This is especially a risk if you are exercising outdoors.3

During the colder and harsher weather typical of the winter season, you’re more likely to spend more time indoors. This can increase your exposure to indoor allergens such as dust mites, mould, pet dander, and insect droppings, which may cause an allergic reaction or asthmatic symptoms.

Indoor Allergens
Many indoor allergens such as dust mites and pet dander can cause allergy and asthma symptoms. While dust mites can be found throughout the house, these microscopic creatures thrive in warm, humid environments such as bedding, upholstered furniture, and carpeting where they feed on dead skin cells.

Hot Weather
High heat and humidity can trigger allergy and asthma symptoms in the summer. Breathing in humid air in the summer, which is saturated with water, activates the nerves that cause your throat to tighten.5

Humid air also traps allergens, pollution, and ozone (a gas that can irritate the respiratory system) in the atmosphere, which you can easily breathe in.

Thunderstorms
Thunderstorms in the spring and summer can trigger an allergic reaction or asthma symptoms.6 When it rains, pollen grains absorb moisture and burst open, releasing hundreds of pollen fragments into the atmosphere that can enter and irritate the airways of the lungs.

Humidity
Relative humidity refers to the amount of water vapor in the air. To prevent allergy and asthma symptoms, the ideal relative humidity is 35% to 50%.7 This can be achieved by using a humidifier (increases water vapor) or dehumidifier (increases water vapor).

When humidity is above 50%, dust mite and mould growth can be encouraged. When humidity is less than 30%, it can cause dry nasal passages and skin and irritate the airways.

Symptoms
Up to 80% of childhood asthma and more than 50% of adult asthma cases are caused by allergies.8

You may experience allergy symptoms such as:

Nasal congestion
Runny nose
Scratchy throat
Sneezing
Itchy, red, or watery eyes
The classic asthma symptoms are more severe and include:9

Shortness of breath
Frequent coughing (especially at night)
Wheezing (whistling noise during breathing)
Chest tightness
Treatment

There are a variety of long-term asthma control medications. Some are used alone, while some are combined with other drugs. These treatments are commonly used to treat seasonal asthma and other types of asthma.

Inhaled Corticosteroids
Inhaled corticosteroids (ICS) are medicines that are commonly used to alleviate asthma symptoms. ICS medications reduce inflammation and mucus in the airways, which can help you breathe better.10

These drugs are inhaled through a metered-dose inhaler (MDI), dry powder inhaler (DPI), or a nebulizer. People who have moderate or severe persistent asthma must use ICS medications daily.

Combination Inhaler
Combination asthma inhalers are used for the long-term control of asthma symptoms.11 They combine two different inhaled medications: a corticosteroid and a long-acting beta-agonist (LABA).

Corticosteroids reduce inflammation and mucus production, while LABAs are long-acting bronchodilators that widen and open constricted airways.

Rescue Inhaler
A rescue inhaler (also known as a short-acting beta-agonist bronchodilator) helps to expand a person’s airways during an asthma attack.12 When inhaled, the medication relaxes the muscles in the airways and causes them to widen.

Rescue inhalers use short-acting medication, which provides relief from symptoms within 15 to 20 minutes.

Leukotriene Modifier
Leukotrienes are molecules your cells produce that cause airway constriction, excess mucus production, and inflammation and swelling in the lungs.13 Leukotriene modifiers are medications that act on leukotrienes and can be used to treat mild persistent asthma and hay fever (allergic rhinitis).

Depending on the type prescribed, most leukotriene modifiers are tablets taken at least once a day and are not to be used for asthma attacks. A common type is Singulair (montelukast).

Immunotherapy
Allergen immunotherapy (also known as allergy shots) is a form of long-term treatment for people with seasonal asthma, hay fever (allergic rhinitis), and conjunctivitis (eye allergy). Allergy shots decrease your sensitivity to allergens and lead to lasting relief of allergy and asthmatic symptoms.15

Mast Cell Stabilizers
Mast cells are found throughout the body, including in the airways in the lungs. Mast cell stabilizers are medications that reduce asthma symptoms by preventing mast cells from releasing inflammatory substances.16

These medications are typically used in the long-term treatment of asthma.
Lifestyle Changes
There are ways you can reduce your exposure to allergens and irritants that may provoke asthma.

Avoid Pollen
You can avoid pollen by staying indoors and closing your windows when these levels are high. If you garden or rake, wear a HEPA filter mask to reduce the number of pollen particles that get into your lungs.
Reduce Pet Dander
Pet dander is composed of tiny, microscopic flecks of skin shed by cats, dogs, or other animals with fur or feathers.17 Consider creating a "pet-free zone" such as the bedroom. That reduces exposure to pet dander, which can easily stick to furniture, bedding, and clothing and travel through air vents.
Clean Well and Often to Reduce Dust Mites
Dust mites live in fabrics and carpets. To reduce dust mites, wash beddings in hot water weekly and wrap your pillows, mattress, and box spring in dust mite-proof covers.7

Eliminate Leaks in Home
Leaks, cracks, gaps, and holes in the ductwork of your house allow dust, dirt, and other types of allergens to settle inside piping and air ducts. To prevent allergens from entering your home, seal leaky pipes and air ducts with the help of a technician.

Avoid Problematic Weather
Each season can expose you to different allergens, which release histamines that can trigger allergy and asthmatic symptoms. To minimize allergies, avoid going outdoors when it's too hot, cold, dry, or wet. These conditions can trap and circulate allergens, making it easy for you to breathe them into your lungs.

When to See a Healthcare Provider
Some allergy and asthmatic symptoms can be self-managed with medication and lifestyle modifications.

If your symptoms interfere with your daily activities, remain the same, or become worse, consider seeing an allergist (a doctor who specializes in allergy and asthma). They can perform allergy tests and help you create an effective treatment plan.

Summary
Different seasons feature allergens and irritants that trigger asthma symptoms. These include pollen and ragweed, mold and mildew, cold weather, humidity, and more.

There are a variety of long-term asthma control medications. Some are used alone, while some are combined with other drugs. These treatments are commonly used to treat seasonal asthma and other types of asthma.

Several lifestyle changes can effectively prevent allergy and asthma symptoms. These include avoiding pollen and reducing dander.

READ ORIGINAL ARTICLE