As the weather gets warmer, the flowers bloom, the trees show their leaves—and the pollen comes out. For close to 40 million Americans, spring is time for seasonal allergies. For most people, seasonal allergies just mean coughing, sneezing watery eyes, and generally cold-like symptoms that last for months. For people with asthma, however, allergens in the air make it worse.
Allergies are similar to autoimmune disease, in that the immune system is defending the body against something that isn’t a thread—the body’s own organs in autoimmunity, and allergens such as tree pollen in allergies. In addition to tree pollen, inhaled allergens can include dust or mold, and these may be more prevalent in different weather conditions or seasons.
Not all allergic reactions lead to asthma symptoms, and not every allergy sufferer has asthma, but in people with both conditions—around half of all asthma sufferers are believed to also be allergic to inhaled particles—allergic reactions can lead into asthma attacks. That’s because the inflammation characteristic of asthma makes the bronchial tubes in the lungs particularly sensitive to irritation, which worsens the inflammation and makes breathing difficult. Other things can also trigger asthma, such as colds—which can occur in spring and summer as well as in colder months—smog, and cigarette smoke. Even cold air, particularly dusty air conditioning, can trigger an attack.
There are some treatments that are used for allergies and asthma alike. Medications to stop the immune system from responding to harmless allergens work by preventing the release of chemicals that signal the inflammation that leads to an asthma attack, meaning the allergens won’t cause a reaction or trigger asthma. A different sort of medication, called a leukotriene modifier, also modifies the immune response, in this case by acting directly on the chemical compounds in the body that are responsible for inflammation.