Allergies are abnormal immune system reactions to things that are typically harmless to most people. When you're allergic to something, your immune system mistakenly believes that this substance is harmful to your body. Allergic reactions are sensitivities to a specific substance, called an allergen , that is contacted through the skin, inhaled into the lungs, swallowed, or injected.
The most common allergens are pollens, molds, dust, and animal dander. If you have seasonal hay fever, tree pollen, grasses or weeds may trigger your symptoms. If you're sensitive to indoor allergens such as dust mites, cockroaches, mold or pet dander, you may have year-round symptoms.
Some allergens are present only during certain seasons, for example, ragweed in the fall. The allergic reaction they cause is called seasonal allergic rhinitis or hay fever. Other allergens are present year-round, such as the mites in house dust. Hay fever is the common name for an allergic response to specific substances in your environment. Hay fever is one of the most common allergic conditions, affecting about 40 million people in the United States.
In an attempt to protect the body, the immune system produces IgE antibodies to that allergen. Those antibodies then cause certain cells in the body to release chemicals into the bloodstream, one of which is histamine (pronounced: his-tuh-meen). The histamine then acts on a person's eyes, nose, throat, lungs, skin, or gastrointestinal tract and causes the symptoms of the allergic reaction.
Allergic reactions vary. They can be mild or serious. They can be confined to a small area of the body or may affect the entire body.Anaphylaxis is a severe allergic reaction that may occur when you come into contact with something you are allergic.Symptoms of the reaction usually start within minutes to an hour or two after contact with the allergen. In rare cases, symptoms may occur up to 4 hours later.In addition, your body responds to the allergen by releasing chemicals such as histamines, which cause allergic rhinitis or hay fever,swelling of the skin, a red rash, and severe itching.
Most occur within seconds or minutes after exposure to the allergen, but some can occur after several hours, particularly if the allergen causes a reaction after it is partially digested. In very rare cases, reactions develop after 24 hours. You have had allergies since you were a child, you will probably have them the rest of your life. New allergies can develop any time, even if you have not had allergies before. Allergy symptoms depend not only on the season and weather but also on location. This means your allergies may wax and wane, depending on where you are living.
Hayfever suffers seem to be highly sensitive not only to typical seasonal allergy triggers like grass and tree pollens, but also to things like cold air, perfumes, cigarette smoke, household cleaning products, and even exercise.
According to a new study, people with hayfever or seasonal allergic rhinitis are more likely than those without seasonal allergies to react when exposed to these "non-allergic triggers," Dr. Dennis Shusterman of the University of Washington, Seattle, reported at a gathering of asthma and allergy specialists in San Diego this week.
Shusterman and his colleagues studied non-allergen triggers among 60 adults between 19 and 68 years old with and without a history of allergic rhinitis.
They found that the majority of subjects who reported reacting to more than three of the non-allergic triggers had a history of allergic rhinitis.
Specifically, 42 percent of seasonal hayfever sufferers reported more than three non-allergic triggers like cold air, perfumes and tobacco smoke, compared with only 3 percent of subjects without a history of allergic rhinitis.
"Interestingly," Shusterman said, "a previously published study came up with very similar numbers so I think this is a very real phenomenon in which there is a subset of allergic rhinitics who are also responsive to non-allergic triggers."
People in the study who were older than 35 years of age were more likely to report one or more non-allergic hayfever triggers, particularly tobacco smoke.
Without proper treatment, hay fever can impair your quality of life, cause sleeplessness, fatigue and irritability that affect your performance at work or school, and increase your risk of developing more serious allergic conditions such as asthma or eczema.
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