Indoor Allergies

An allergy is a damaging immune response that the body has to a particular food or substance.  Whether we start sneezing in a dusty room, or get itchy from wearing a wool sweater, most of us experience allergic reactions at some point in our lives.  For some people it can seriously impact quality of life.

Indoor allergies are triggered by substances that are found inside our houses – usually dust mites, cockroaches, molds and animal dander.

Incidence; Causes and Development

Indoor allergies affect an estimated 1-in-3 people in the U.S.

Exposure to any number of different allergens can cause allergy symptoms.  These allergens are everywhere, with a surprising number in your home.

Signs and Symptoms

The most common symptoms are nasal congestion, sneezing and itching of the eyes (in about half of cases), nose, throat or skin.  For those with asthma, an allergic reaction can also trigger an asthma episode.  Allergic symptoms range from mild to debilitating.

Diagnosis and Tests

Knowing what causes your allergies will help you to focus your efforts in controlling them.  When you visit your doctor, he or she will begin by taking a detailed history of your symptoms and when they occur.  Are they seasonal or year-round?  Are they worse when you are indoors or outdoors?  Are they more of a problem during the day or night?  To confirm suspected allergies, allergy testing may be conducted by an allergist.

Treatment and Prevention

Fortunately there are many ways to control and prevent the symptoms.  The best way to prevent allergies is to avoid the allergens that trigger your symptoms by making changes to your indoor environment, and by choosing your outdoor environment more carefully.

Reducing exposure to the offending allergens through indoor environmental controls is usually the least expensive and, in many cases, the most effective method for managing allergies.  Even if your allergies require medications and/or immunotherapy, environmental controls should always be an integral part of your treatment plan.  The most common indoor allergens are house dust mites, cockroaches, indoor molds and animal dander.

Dust mites are around 0.25mm or 1/100th of an inch in size and are found in their millions in most houses

Dust mites are microscopic creatures that live in our homes.  Their waste products and decaying bodies are a year-round problem.  To reduce your exposure to dust mites, it is most important to focus on your bedroom.  You spend more time in this room than any other in the house, so it is here that your efforts will have the greatest impact.  Some of the likely sources of exposure are your pillow, mattress and bedding where they tend to live.  The following steps are essential to reducing this exposure:

• Encase your mattress and box spring in an allergen-impermeable cover.
• Encase your pillow in an allergen-impermeable cover or wash it weekly in hot water (55°C or 130°F is necessary to kill mites.)
• Wash sheets, blankets and comforters weekly in hot water.
• In a child's bedroom, stuffed animals can be a significant source of dust mite exposure.  Sleeping with stuffed animals should be limited for a child who has a dust mite sensitivity.  If one or two are necessary, they too should be washed regularly in hot water.
• Helpful too is reducing indoor humidity to less than 50% (dust mites thrive in areas of high humidity.)
• When possible, remove carpets and use washable rugs, especially in the bedroom.
• Avoid sleeping or lying on stuffed furniture.

Regular vacuum cleaning is important.  It should preferably be done by someone other than the allergic individual and while he or she is not out of the room.  If this is not possible, the allergic individual should wear a dust mask while vacuuming.  Essential is a vacuum cleaner with a good filtration system and/or special vacuum bags that have two layers to keep dust from escaping.  These bags are available for most brands of vacuums from allergy supply companies.

Cockroaches can cause allergies through proteins in their droppings, saliva secretions, and their shed skins after molting

Cockroaches have become increasingly recognized as a potent indoor allergen, especially in inner cities.  If someone in your household is sensitive to cockroaches and roaches are present in your home, it is essential to eliminate them.  After removing them, keep them away by cutting off their food supply.  It is also important to do a thorough leaning of the areas they inhabited.  The allergens from cockroaches are their waste product, decaying bodies and saliva.  Once the roaches are gone, these will continue to cause allergic reactions if they are not removed by cleaning.

Pets produce dander (flakes of dead skin), saliva and urine, all of which can be allergenic.  The most effective way to get rid of these allergens is to remove the pet from the home and many allergists would argue that this is essential.  Although giving away a pet can be an upsetting experience, it is often the only solution that eliminates the allergic person's discomfort and allows him or her to live a healthier life.  This is particularly important for those whose allergy triggers asthma.

If removing a pet is not an option then the next most effective solution is to keep the animal out of the allergic individual's bedroom.  If forced air heating or air-conditioning is present, cover the air ducts that lead into that person's bedroom with a filter or, even better, close off the duct with plastic and heat the room with an electric heater.  Having a non-allergic person wash the pet weekly (washing in water works as well as expensive pet shampoos) also helps.

Indoor mold sources include damp basements, showers stalls and curtains, room humidifiers, refrigerator and dehumidifier pans, and houseplants.  Mold grows best in places that are damp and dark.  To reduce mold growth in these areas, provide lots of light and adequate ventilation and make sure bathrooms are properly vented.  Dehumidifiers can be helpful, especially in damp basements.  A simple method to remove mold is to clean surfaces with a solution of one part bleach to 10 parts water.

Seek medical attention if...

A general rule of thumb relating to eye problems is: "if it itches, it's allergy; if it burns or stings, it's probably dry eye; and if the eyelids stick together in the morning, with crusts on the eyelashes, it's bacterial conjunctivitis."  Some of these conditions don't call for a doctor's visit but severe pain or loss of vision warrants an immediate call to the eye doctor.