Allergy to Outdoor Mold Spores

If you have an allergy that lasts almost all year round, you may be suffering from a sensitivity to mold spores. Molds can grow anywhere. If a mold source is disturbed, mold spores can disperse. The allergens produced by molds are found in mold spores, and inhaling these airborne spores can cause the allergic reactions.

What is a mold spore?

Mold spores are seeds of molds and fungi. Outdoor mold spores grow in moist shady areas, such as soil, decaying leaves, compost piles, and rotting wood. Mold spore counts are higher when it rains or when the weather is very humid. They would also grow during harvest season, around the barn and in stacks of hay.

Unlike pollens, the dispersal of outdoor mold spores is not as seasonal. Some are released in dry, windy conditions, while other spores are released in high humidity when there is fog and dew. Actually, molds disperse spores anywhere that’s damp and humid, at any time of the year, and individuals who are exposed to such damp environments experience allergic reactions that last for quite a long time.

What causes a mold spore allergy?

Since they are everywhere, they are not easy to avoid. Inhaling mold spores causes allergies. You are exposed if you walk through moist uncut fields, work on a compost pile or dry soil, cut grass and rake leaves.

There are many types of outdoor mold spores but only a few are allergenic. The most commonly found molds are Alternaria and Cladosporium (Hormodendrum). Other allergenic outdoor molds include Helminthosporium, Epicoccum, Fusarium, Mucor, and Rhizopus are the major culprits. These mold spores can be recognized under a microscope.

What are the symptoms?

Outdoor mold spore allergies are triggered by inhaling the spores. The primary symptom is allergic rhinitis, or hay fever, wherein the mucous membranes of the nose and sinus areas are inflamed. There is sneezing, nasal discharge, nasal congestion and dry, scaling skin. The eyes, however, are rarely affected, unlike with pollen allergies, conjunctivitis may develop. If the inhaled mold spores reach the lungs, the individual might develop asthma. Symptoms may last the entire year depending on the severity of the allergy.

Sometimes, eating foods such as cheeses processed with fungi, mushrooms, dried fruits, and foods that contain yeast, soy sauce, or vinegar can cross-react with the mold spores and worsen the symptoms.

People are more likely to have a mold spore allergy if any family member is allergic to other airborne substances such as pollen and animal dander. Farmers, dairymen, loggers, mill workers, carpenters and woodworkers, gardeners, wine makers, and furniture builders, and those whose job requires them to be exposed to molds each day have a higher risk of developing allergies.

How can a mold spore allergy be prevented?

You cannot cure a mold spore allergy, but there are ways to prevent allergic reactions by reducing your exposure to the allergens.

When outdoors, avoid walking through decaying vegetation, compost piles, and fallen leaves because you might inhale mold spores. Avoid doing yard work, such as lawn mowing and raking leaves on a hot, humid day. Avoid farms, especially during harvest time when mold spores could be growing around the barn or under a stack of hay. And wear a face mask outdoors if possible.

This has been quite a year for mold allergy sufferers as the rain, especially late afternoon and evening rain, is making the mold spores grow, and this in turn, kicks in the mold allergies.

If you are susceptible to mold allergies, you may want to find another home for your outdoor plants during the winter months (even the garage if you are in a milder climate). Plants can harbor mold spores and unless you consistently remove dead and drying leaves, the plant may aggravate your allergies.  Others argue that plants are good for the air in cleansing and purifying it, so it mostly depends on your specific allergies.

I’ve noticed that my daughter has had those allergy eyes for the past few days and even an itchy mouth she said. At first I thought it was dust as she just cleaned out her closet, but that was a few days ago, and she still has the dark eyes. We had a lawn service here the other day, and he noticed a brown spot of grass. This, he told me, was due to fungus caused by excess water, though the rest of the yard is dry. Sometimes hard to make sense of, but the fungus and mold is bad this year. I think that is what is hitting my daughter.

It may not be just rain that is making the mold grow, but high humidity levels as well, and this year we are seeing record high humidity. I know in the south if you just walk outside your hair gets big and sweat runs down your back, to me, that is enough to tell me the humidity is high!

I know it is important to treat a mold allergy as any other, avoidance is best. But that is not always possible. However, I do try to keep my daughter inside with air conditioning a lot right now, and I try to keep the humidity in the house low. Using central air conditioning with a HEPA filter will help trap the spores before they get in the air.

My daughter has taken more than her fair share of benadryl in the last week or so, and with school starting next week, I think we may try to squeeze in a visit to our alternative practitioner. I hate to send her off to middle school with those dark circles under her eyes and sneezing the day away.  And I think it is just getting hotter, here, we’ve got a good ten weeks or so until our heat breaks.


  1. I have Asthma and bad allergy to molds. I am in Ohio and it is hot and humid and mold spores are over 3,000, high. I live in an apartment and must do my laundry in a laundry room with no A/C (when I have multiple allergies and must keep a 1300 3M filter in and KEEP THE WINDOWS SHUT YEAR ROUND). Worse, I live first time with a broiler system and have hard time with this but no money to move. How can I do my backed up laundry without bringing in the mold and the ragweed which is 68 – my second worst allergy?

  2. Additional noteworthy comment: It is nighttime and I breathe easier, but cannot locate information if Mold Spores go down at night time. The door to laundry is left open . . . so. I must wash my allergen pillows in front loading washing machine so I go to indoor “wash here and dry for free” but do not know if they have mold and pollen catching filters. So, I am guessing its best to go to this place and ALL MY LAUNDRY RIGHT NOW. I NEVER OPEN MY CAR WINDOWS EITHER; HOWEVER, I DO PUT MY PILLOWS AFTER FULLY DRY IN TRASH BAGS AND CARRY THEM OUT AND IN, WIPE DOWN TRASH BAGS AND THEN REMOVE. I have multiple illness such as fibromyalgia, chronic bronchitis, dry scaly skin during mold high counts, migraines, autonomic nervous system instability (anything n auto pilot in my body not work good, goes to overheated and slams to 93 degree oral temperature (beginning hypothermia condition in the winter – nuerologist Dr. said it was from 105.6 degree temperature from spinal meningitis at age 8 and going out of ice tubes and out because they could not control my body temperature, therefore effecting this Auto Nervous System’s ability to control extremes. The excess amount of energy it takes to do these things why fybro causes fatigue is difficult. I am 51 and on disability and had first Asthma attack in 7th grade track meet and was forced off track team. I was born with bronchitis. Help please. Controlling my exposure at the “least amount of effort would be most beneficial to me. I also have hypothyroidism and hypoglycemia (only treatment for that is thyroid medicine and eat six to small meals a day — which exhausts me doing all those dishes. UGH.

  3. Guess I will draw back and punt on doing my laundry, have one towel left clean and a few rags. All laundry is in bags due to exposure to outdoor activity before humidity and high mold count. No one is responding. Perhaps I should print this and go back to my 1980 allergist again. He should be able to help me; but I am broke at the moment, even if I bought new towels I would need to wash them. Miss having my own laundry room in home; but good to be divorced from an abusive — that is a better trade off.

  4. I am trying to find out if there is anything tying together bronchiectasis and outside mold. My sister has bronchiectasis and is getting worse. Her backyard is full of large mold spores, as well as the front yard that has black mold on some rocks. She is not doing well and I want to know if there is anything more that can be done that might not be being done. I am desperate to help her as we are the only 2 left in my immediate family. If you can help with maybe some natural suggestions, I’m open to listen to just about anything right now. Please help

    Broken hearted,
    Brenda K. Nummer

  5. Was living through this MOLD HELL and tried just about anything to help myself (i.e., herbals, essential oils, vitamins, minerals, etc.). These things would help for a short while but then symptoms returned. In what seemed my endless search for remedy, I came across this research by Walter Last. I was so DESPERATE for help that I was willing to try anything; and his research was rather CONVINCING. And I am SO GLAD I DID. I am completely symptom free but I am more than 80% BETTER.
    Pseudohyphae and hyphae can be seen in the blood of individuals with cancer and autoimmune diseases. Candida can also form tough layers of biofilm. This same study shows that Borax inhibits the formation of biofilms and also the transformation of harmless yeast cells into invasive hyphal form. Other articles have shown that this process, commonly initiated by antibiotics, is a basic cause of most of our modern diseases, and this makes Borax and Boron primary health remedies. Boron is also used to remove accumulated fluoride and heavy metals from the body(14).

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