Mold: Surprising Fall Allergy Culprit

Take autumn rainfall, mix it with decomposing leaves, and you've got the perfect recipe -- for mold.

While pollen reigns as the most common fall allergy culprit, mold -- spore-breeding fungus -- is the second most prevalent ingredient in the batch of allergens that cause allergy-related symptoms, from the mildly annoying to the downright debilitating.

That mold is a powerful presence during fall comes as a surprise to many people, who erroneously equate it strictly with summer and believe they have to contend only with ragweed in autumn. But, say experts, humid and cooling conditions, coupled with decomposing leaves and other matter, can create a frenzy of mold activity in the fall. In fact, colder states generally experience peak mold counts during October, according to the American Academy of Allergy Asthma & Immunology (AAAAI).

"Although it's not as dramatic as ragweed, we get a burst in mold activity in the fall," confirms S. Michael Phillips, MD, head of Clinical Allergy and Immunology Services at Penn Presbyterian Medical Center. Some molds are also referred to as mildew.

Fighting Fungus

If you live in an area that's conducive to mold and suspect that you're allergic to it, try these tips to minimize its effects, inside and out.

Reducing Outdoor Mold Growth

• Get rid of free-standing water -- in overturned trash cans, empty pots, wherever. It's not good enough to clean up your own backyard. Because mold spores can blow significant distances, ask your neighbors to cooperate, too, Phillips suggests.
• Try to minimize the shade in your yard. Bright sunshine dries up the ground, leaving less opportunity for mold growth.
• Rake up leaves on a regular basis, and clean out your gutters.
• If you go outside, avoid doing so after it rains.
• On windy days after rainfall, minimize outdoor exposure and keep your windows shut.

Combating Indoor Mold

• Check your attic and basement for water leaks and mold growth, advises Phillips.
• Keep the humidity level in your house under 50%. Humidity detectors are simple, small, and inexpensive devices that can be found at home improvement stores. "People tend to over-humidify their homes," says David Rosenstreich, MD, an allergist with New York's Montefiore Medical Center. Rather than keeping the thermostat high and the humidifier cranked up during cold months, he suggests lowering the thermostat and reducing the use of a humidifier.
• If you suspect mold in your home, getting an environmental service to test it will give you the most accurate assessment, says Rosenstreich.
• If you detect mold, remove it with bleach -- a half cup per 5 gallons of water -- recommends Phillips.

Just how harmful is mold? That depends in part on the type of mold. "Only a few molds cause human disease," Phillips tells WebMD. Most species -- there may be up to 100,000 -- we should welcome. "Their activity breaks down plant and animal material into basic building blocks so that the nutrients can be recycled into foods vital for plants and animals," Phillips says.