Читать книгу Allergy-Proof Your Life - Michelle Schoffro Cook - Страница 9

Spring allergies affect an estimated 25 million Americans.1 Caused by an immune system overreaction to airborne pollens or other substances, spring allergies are commonly called seasonal allergies, hay fever, or allergic rhinitis.

Your immune system is your body’s defense against foreign invaders; it works hard to protect you against bacteria, fungi, yeasts, viruses, toxins, and other substances that may compromise your health. We simply could not live without a strong immune system, but sometimes this impressive internal system can go a bit haywire, reacting to common, everyday substances.

Allergies are caused by your body’s reaction to certain substances known as allergens that your body considers foreign invaders rather than the harmless substances they really are. When your body comes into contact with a specific allergen for the first time, it secretes a substance known as immunoglobulin E (IgE), an antibody specific to that allergen. IgE then attaches to the surface of specific cells in your body known as mast cells. These mast cells are found in large numbers in mucous membranes of your nose and in your skin, among others. They work to regulate inflammation by releasing various chemical compounds, including histamine.

After the first encounter with an allergen, future encounters cause a cascade of chemicals known as histamines, leukotrienes, and prostaglandins, which further triggers a range of allergic symptoms, including coughing, itchy eyes, nasal congestion, runny nose, sneezing, and sore throat.

The specific compound called histamine can even cause our airways to constrict, as in the case of allergy-induced asthma attacks, or cause blood vessels to become excessively permeable, causing fluid leakage or hives. Leukotrienes cause excessive secretion of mucus and the resulting signature symptoms of allergies: runny nose and increased mucus. Other substances known as prostaglandins can stimulate the release of histamine in the body, resulting in airway or tissue inflammation and a wide range of allergic symptoms.

The most common allergens include pollens, mold spores, dust, airborne contaminates, dust mites, pet dander, cockroaches, and environmental toxins, particularly those found in vehicle exhaust, cleaning products, personal-care products, and food additives. Every person is unique and, as a result, can have unique reactions to environmental substances. You can also develop a new allergy to something that was previously harmless. Alternatively, you can lose allergies just as quickly as they arrived, although that is uncommon unless you take certain measures to strengthen and balance your body’s delicate immune and hormonal systems.