722true dots bottomright 231true true 1200none
  • 5000 fade true 60 bottom 30
  • 5000 fade true 60 bottom 30
  • 5000 fade true 60 bottom 30
  • 5000 fade true 60 bottom 30
  • 5000 fade true 60 bottom 30
  • 5000 fade true 60 bottom 30

Mold Allergy


Molds live everywhere. Disturbing a mold source can disperse mold spores into the air, triggering an allergic response in some people.


This fact sheet describes mold allergy, how to manage an allergy to mold, and how to prevent mold growth in the home. We hope that this material helps you better understand the nature of mold allergy and what to do about it. Please keep in mind that this information is not meant to take the place of medical advice from your own physician.


When Arnold brought his elderly mother to live with

his family, he quickly converted the basement into a bedroom for his 11-year-old twins and put his mom in their upstairs bedroom. After about three months, one of the boys began to develop allergy symptoms. They tried various medications, but nothing really worked. Finally a consultation with an allergist helped them understand the potential problems of mold allergy in the basement and the risk of increasing symptoms. After learning how difficult it can be to prevent mold growth in basements, Arnold decided to build an addition on his house to create the extra space they needed.


What is mold?

Mold is another term for fungus (mold and fungus are the same thing). The plural of fungus is fungi. When talking about more than one kind of mold, we can use the word fungi. Molds differ from plants in how they reproduce and grow. The seeds of fungi are called spores. They are spread by the wind outdoors and by air indoors. Some spores are released in dry, windy weather. Others are released with the fog or dew when humidity is high.

There are many kinds of mold. Some molds form colonies, which you can see with the unaided eye. Other types of molds are only visible when viewed under a microscope.

Many molds grow on rotting logs and fallen leaves; in compost piles; or on grasses and grains. Unlike pollens, molds do not die with the first frost in the late fall or early winter. Instead, most outdoor molds become dormant during the winter. In the spring, they grow on plants killed by the cold.

Indoors, mold grows wherever there is a source of moisture, particularly in the bathroom, kitchen, or basement.

Although there are many types of molds, only a few dozen are known to cause allergic reactions. Molds most likely to trigger an allergic response include the following:

•             Alternaria

•             Aspergillus

•            Aureobasidium (Pullularia)

•            Cladosporium (hormodendrum)

•             Epicoccum

•             Fusarium

•             Helmin-thosporium

•            Mucor

•             Pencillium

•             Rhizopus


What is an allergy?

An allergy is an adverse reaction from an immune response to something that contacts the body, is inhaled, or ingested. The reactions include sneezing, wheezing, cough, itching, skin rashes, stomach pain, diarrhea, or even a fall in blood pressure, which can cause dizziness or passing out. With proper management and education, people with allergies can lead healthy, normal lives.


Who gets mold allergy?

It is common for people to develop an allergy to one or more types of mold if they, or other family members, have a history of allergic responses to things such as pollen or animal dander.

Some people may become allergic only to mold or they also may have problems with other allergens such as dust mites, pollen, or certain foods.


Good to know . . . If you have an allergy to mold, you likely will not be allergic to all types of mold. Mold spores have only limited similarities, and your body probably will only be sensitive to some of them.


People in some occupations have more exposure to mold and are at greater risk of developing a mold allergy. These workers include:

•            Farmers

•            Dairyworkers

•            Loggers

•            Bakers

•            Mill workers

•            Carpenters

•            Greenhouse employees

•            Winemakers

•            Furniture repairers


What are the symptoms of mold allergy?

When mold spores are released into the environment, they can deposit on the inside lining of the nose, causing hay fever symptoms. The spores also can reach the lungs, triggering asthma symptoms in sensitive individuals. In rare cases, a serious illness called allergic bronchopulmonary aspergillosis develops.

In general, the symptoms of mold allergy are very similar to the symptoms of other allergies. If you have an allergy to mold, you may experience some of the following symptoms:

•             Sneezing

•            Runny or stuffy nose

•            Itching of the throat, or inside the ears

•             Hives

•            Swollen eyelids, itchy eyes

•            Cough, wheezing, or difficulty breathing


Some people with mold allergies experience seasonal symptoms due to outdoor molds. However, if you are allergic to molds found indoors, you may have symptoms year-round.

Sometimes the allergic reaction to mold exposure is immediate. For some people, the reaction can be delayed.


How is mold allergy diagnosed?

To diagnose an allergy to specific molds, your physician will begin by asking questions about your experiences when you are in certain kinds of places or eat specific foods.

Prepare a log for your visit to the physician. Keep a record of your allergic reactions for several weeks before your appointment. Record where you were, what you were doing or eating, what the reaction was like and how long it lasted. Note any medications— including over-the-counter medicines—you may have used and the results.

If a mold allergy is suspected, the physician often will do a skin test to determine exactly what molds are causing the reaction. In a skin test, tiny extracts of different types of molds will be put on or under your skin after it is pricked with a small needle. A positive reaction shows up as a red, raised area around the pricked site. If there is no reaction, an allergy is not suggested. Your medical history and physical exam, along with results from your skin test and possibly a blood test, will help your physician diagnose a mold allergy.


What is the treatment for the condition/situation?

The best treatment for mold allergy is avoiding mold exposure and taking steps to reduce or eliminate mold spore growth wherever you can. Here are some suggestions.

Avoid contact. Keep away from areas known to harbor mold spores. Mold that grows on houseplants can cause an allergic reaction, but this is only likely to happen if the soil is disturbed.

Reduce indoor humidity.            If indoor humidity is above 50 percent, the risk of mold growth rises steeply. Hygrometers can be used to measure humidity accurately. The goal is to keep humidity below 45 percent, and preferably at about 35 percent. Use an electric dehumidifier to remove moisture from the basement. Be sure to drain the dehumidifier regularly and clean the condensation coils and collection bucket.

Use central air conditioning with a HEPA (High Efficiency Particulate Air) filter. These filters help trap spores before they reach you. Air conditioning with a HEPA filter attached works better than electrostatic air- cleaning devices and much better than freestanding air cleaners. Devices that treat indoor air with heat, ions, or ozone are not recommended.


Take medications properly. Some people find relief of allergy symptoms by using over-the-counter (no prescription needed) medications. However, if these medicines fail to relieve your symptoms or cause unpleasant side effects, you should talk with your physician about prescription alternatives. For moderate and severe allergy symptoms, your physician may prescribe ongoing use of medications.


How can mold growth be controlled in the home?

The more you are able to prevent the growth and distribution of mold spores, the more likely you are to reduce your exposure to mold. There are a number of things you can do to keep mold from developing into a problem in and around your home. Here are some suggestions.

•            Put an exhaust fan or open a window in the bathroom

•            Quickly repair any plumbing leaks.

•            Repair blocked drains and water seepage through basement walls.

•   Raise the temperature in the basement or other damp areas to help lower humidity levels. Small space heaters or a low-wattage light bulb may be useful in damp closets. Be careful where you place them, though, to avoid creating a fire hazard.

•            Fix poorly vented clothes dryers.

•            Remove bathroom carpeting where moisture is a concern.

•            Clean garbage pails frequently.

•            Scour sinks and tubs at least monthly.


Cleaning curtails mold spore growth! Molds thrive on soap and other organic films that coat tiles and grout. For problem areas, use a commercial bleach solution like Tilex, which has been shown to kill molds and neutralize their allergens. It is not a good idea to mix your own solution as bleach can trigger an asthma attack.


•   Add fungicides to paint, primer, or wallpaper paste to slow fungus growth on treated areas. (This approach has little effect if excess moisture remains.)

•            Clean refrigerator door gaskets and drip pans.

•   Polyurethane and rubber foams seem especially prone to developing fungus growth. If bedding is made with these foams, it should be covered with plastic.

•   Get rid of old books, newspapers, clothing, or bedding—places where mold spores can thrive.

•   Promote groundwater drainage away from your house. Remove leaves and dead vegetation near the foundation and in the rain gutters. Completely shaded homes dry out slowly. Dense bushes and plant growth around the foundation often promote dampness. In the winter, condensation on cold walls encourages mold spore growth. Even thick insulation can be invaded if vapor barriers in exterior walls are not effective.


When should I see an allergy specialist?

Many patients are treated for allergies of all kinds by a pediatrician, internist, or family physician. However, if your allergy symptoms are not under control within 3-6 months, or if you have severe persistent allergy symptoms, or if your allergy symptoms require emergency treatment, it may be time to see an allergy specialist. Allergists/Immunologists are specialists who treat allergies, including mold allergy. Those who have completed training in those specialties are usually called board-certified or board-eligible.


Does health insurance cover treatment for mold allergy?

Most health insurance plans provide some level of coverage for allergy patients. Check with your insurance carrier for details. Some things you may want to find out might include:

•   Do you need a referral to an allergy care specialist from your internist, family physician, or pediatrician?

•   Does the insurance carrier offer any patient education or specialized services related to allergy? Mold? Indoor air quality?

•   What coverage is offered for pre-existing conditions?

•   What medications are not covered by your plan?

(There can sometimes be a delay in approving newly released medications. Your physician may know about them, but your insurance may not cover them yet.)

The information provided in this fact sheet should not be a substitute for seeking responsible, professional medical care.


Reprinted with permission from “Asthma and Allergy Answers,” the patient education library developed by the Asthma and Allergy Foundation of America.