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Indoor Allergens
Indoor Allergens Overview
Most people with asthma or hay fever or other outdoor allergies
think of their home as a haven where they can escape their allergies.
Unfortunately, houses and apartment buildings harbor their own allergens
(agents that cause allergy symptoms). The inside of your home actually traps
allergens, making them impossible to avoid.
- Although many allergens in your environment can trigger allergic
symptoms, house dust is the main culprit in indoor allergies. What is house
dust?
- It varies depending on the type and age of your home, the temperature and
humidity in the home, what you keep in the home (everything from food to
clothes to furniture), and who lives in the home (human, pet animal, and
plant).
- Some dust is present in every home, regardless of how often or how
thoroughly the house is cleaned.
- House dust is an airborne mixture that might contain fine particles of soil
and plant material from indoors or outdoors, particles of human and animal skin
(dander) and hair, fabric fibers, mold spores, dust mites, fragments of insects
that have died and their waste, food particles, and other debris.
- Although many substances in dust can trigger allergic symptoms, the
most important indoor allergens are dust mites, pet dander, cockroaches,
and molds.
- It varies depending on the type and age of your home, the temperature and
humidity in the home, what you keep in the home (everything from food to
clothes to furniture), and who lives in the home (human, pet animal, and
plant).
- Unlike seasonal allergies such as hay fever,
indoor allergies may last all year long. Indoor allergens may provoke or
worsen asthma symptoms, depending on a person's unique sensitivities.
- Indoor allergies tend to be at their worst in the late summer, when dust
mites are at their peaks.
- Allergy symptoms can actually be worse in the winter when the windows are
closed and people are shut in with the allergens.
- Keeping your windows open at night during seasons of high outdoor pollen
and mold count may worsen your allergy symptoms or asthma because these
high-concentration outdoor allergens are allowed into your house to
settle.
- If you are sensitive to indoor allergens, you will continue to have
symptoms as long as you are exposed to your allergens.
- Indoor allergies tend to be at their worst in the late summer, when dust
mites are at their peaks.
- Sensitivity to indoor allergens is very common and occurs at every age. It is less common in children younger than 5 years. People most likely to experience allergic rhinitis are those in early school and early adult years.
Indoor Allergies Causes
An allergic sensitivity is a reaction of the immune system to a foreign "invader," a substance that is not native to your body. Exposure to this invader, an allergen, triggers the reaction.
When the allergen particles come to rest in the linings of the eyes, nose,
or airway of a susceptible person, an allergic reaction can occur.
- When the immune system has been previously "sensitized" to a
specific invader, it overreacts to the invader; this overreaction to a harmless
substance is known as a hypersensitivity or allergic reaction.
- This reaction sets in motion a series of responses that culminates in
release of chemicals called "mediators." Histamine is an example of a
mediator.
- It is the effects of the mediators on cells and tissues that cause allergic symptoms.
WebMD Medical Reference from eMedicineHealth
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