Adult Indoor Allergy Causes, Symptoms, and Relief

Make indoors more comfortable by reducing allergy triggers

A man standing inside with a moving box, and dust particles in the air.

There’s no place like home … for allergies! Just stepping indoors — at home, work, or school — exposes you to numerous allergens. An allergen is any substance which produces an allergic reaction. Millions of people suffer year-round because of indoor allergens.¹  

The most common sources of indoor allergies are dust mites, fungi (mold), mammals (both your pets and invasive rodents), and cockroaches.²  

So basically, the cleaner your home, the stronger your defense against indoor allergies.

Signs and symptoms of indoor allergies

An allergic reaction is the result of your immune system going on the defensive. When it detects an allergen, it produces antibodies called Immunoglobulin E (IgE). In response, your cells release chemicals to fight the allergens, which result in your allergy symptoms.¹ 

The most typical symptoms of indoor allergies include:¹ 

   Runny nose

   Itchy eyes


   General congestion or stuffiness

Here’s where most indoor allergens hide:³

     Damp and humid areas

     Indoor plants


     Pillows and bedding

     Plush furniture

     Plush toys

​​​​​​​     Unsealed mattresses

​​​​​​​     Wall-to-wall carpet

The most common indoor allergy triggers — and what to do about them

Dust mites

House dust mites are a major source of allergies worldwide. Mite-related allergens are more commonly airborne and inhalation of these allergens is the most common way of exposure. Not as common, but mite-contaminated food can also be a source of allergic reactions.2

How to control dust mites:³

   Keep surfaces clean and uncluttered

   Avoid wall-to-wall carpet — use low-pile carpets, washable rugs, hardwood, linoleum, or tile

   Avoid heavy drapes

   Avoid overstuffed furniture

   Use sealed, allergen-resistant covers on your pillows and mattress

   Wash bedding, pillows, and stuffed toys in water that’s at least 130°F; dry them in a hot dryer

Indoor mold

The common indoor mold and mildew that cause allergies thrive in dampness. You’ll find them in moist basements, bathrooms, or anywhere with leaks.1

How to reduce mold¹,³

   Reduce moisture in the bathroom, kitchen, and basement

   Don’t run showers too long before hopping in

   Use dehumidifiers

   Limit the number of house plants, and ensure proper drainage

   Fix leaks quickly

   Remove mold from hard surfaces with water and detergent or, if necessary, 5% bleach; let them dry completely

Pet dander

There are no breeds of dogs or cats that are 100% allergen-free — not even the hairless ones. That’s because you don’t react to fur, but to allergens in saliva, dander (skin flakes), or urine.¹

How to manage pet dander³

   Avoid direct contact with pets

   Keep pets out of your bedroom

   Wash and change pet beds and toys often

   Bathe and brush your pets often — and wear a mask when you groom them

   Wash your hands after handling pets

   Frequently wipe and vacuum spaces where your pets spend time

​​​   Before getting a pet, ask your allergist to determine if you are allergic to animals


The World Health Organization identifies 12 distinct allergens carried by cockroaches.2

How to control cockroaches1,3

   Cover food, garbage, and recyclables; take the trash out quickly

   Use poison baits, boric acid, and traps instead of chemicals

   Block crevices, wall cracks, and windows where they enter

   Fix and seal leaks

   Keep food in lidded containers

   Put away used pet bowls and uneaten food

   Vacuum and sweep after meals

   Wash dishes immediately after use

   Clean under stoves, refrigerators, or toasters where crumbs can accumulate

   Wipe off the stove, cupboards, and other kitchen surfaces regularly

A couple extra tips to minimize indoor allergens

It’s nearly impossible to completely avoid indoor allergens. But there are ways to reduce them.

  • Keep the air as clean as possible3 
    • Increase the flow of outdoor air
    • Reduce humidity
    • Use air cleaners with certified allergy and asthma filters
  • Vacuum the home frequently using a certified asthma and allergy friendly vaccum.
  • Wear a mask while doing housework3 
    • Leave the house for several hours after cleaning it
A woman sits near a window enjoying a warm beverage.

Allegra® is here to help fight indoor allergies

Allegra® helps you live your best life by relieving many common indoor allergy symptoms. If you experience sneezing, runny nose, itchy, watery eyes or an itchy nose or throat, Allegra® Allergy can help. And if you also have nasal congestion, sinus congestion and pressure, or swelling of nasal passages, check out Allegra-D®. Now you can feel more at home — at home.

No matter which product you choose, you can feel good knowing Allegra® is the #1 allergist-recommended medicine brand for non-drowsy relief. 

Find the Allegra® product that’s right for you


  1.  Andrew Moore, MD, reviewed. Indoor Allergens, American Academy of Allergy, Asthma & Immunology [],

    February 28, 2020. May 20, 2021.

  2. Anna Pomés, Martin D. Chapman, Sabrina Wünschmann. Indoor Allergens and Allergic Respiratory Disease, PMC/US National Library of Medicine, National Institutes of Health,

    June 2016. Oct. 5, 2021

  3. Asthma and Allergy Foundation of America, Ed. Control Allergens to Improve Indoor Air Quality, Reviewed by Medical Scientific Council,

    2015. Oct. 5, 2021.

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