A Guide to Mold Allergies

Mold (fungal) allergies can cause congestion, headaches, coughing, wheezing, itchy, watery eyes, and skin rashes. Molds are common in indoor and outdoor environments, where they thrive in high humidity and moisture. However, not all mold spores cause allergy symptoms.¹ The American College of Occupational and Environmental Medicine estimates that about 10% of people have a mold allergy, with about 5% having symptoms, and that 10% to 30% of the population may be sensitive to mold allergens. Depending on your geographic location, outdoor mold allergies may peak in the fall or be year-round.

Symptoms of a Mold Allergy

Mold allergies can develop at any age. The symptoms associated with mold allergies are similar to those of other allergies. They can develop immediately or be delayed. Common mold allergy symptoms include:

• Nasal congestion
• Runny nose
• Headache
• Sneezing
• Sore throat
• Watery eyes
• Dry cough
• Shortness of breath
• Wheezing
• Hives
• Nausea
• fatigue

Mold seems to cause more respiratory symptoms than other allergens, increasing the risk for severe allergies and asthma in susceptible people.

How To Prevent Mold Allergy Symptoms

According to the Environmental Protection Agency, getting rid of all molds and mold spores in your home is impossible. However, the following steps can help reduce mold spores:

• Reduce indoor humidity to 30% to 60%.
• Vent bathrooms, dryers, and other moisture-generating sources to the outside.
• Use dehumidifiers and air conditioning to reduce humidity.
• Increase ventilation throughout your home and use HEPA filters.
• Use exhaust fans when cooking.
• Wipe counters and other hard surfaces with water and detergent, and dry thoroughly.
• Leave wet shoes and clothing in a mudroom.
• Ensure your home has adequate insulation to prevent condensation.
• Avoid carpeting in areas of the home that are prone to collecting moisture, such as bathrooms.
• Remediate any mold safely.

When prevention is not enough to control your symptoms, antihistamines, decongestants, corticosteroids, and asthma medications may be needed to control your symptoms. Contact a doctor on the TelegraMD platform to receive a diagnosis, a personalized treatment plan, and, if appropriate, an online prescription transmitted to your local pharmacy.  

How To Treat Mold Allergy Symptoms

The first step in treating mold allergies is to reduce your exposure. While molds are ubiquitous, reducing moisture and humidity in your home can help relieve symptoms.

The next step is to take allergy medications to control your symptoms:

• Antihistamines reduce itching, watery eyes, sore throat, and post-nasal drip.
• Decongestants reduce nasal congestion and headaches.
• Steroid nasal sprays reduce nasal congestion.
• Nasal saline rinses remove allergens from the nose and sinuses.

If environmental remediation and medications are not enough to control your symptoms and your symptoms worsen or persist, you may want to consider immunotherapy. After having allergy testing, your doctor can prepare an allergy serum that will be used to help your immune system become less sensitive to mold allergens.

You will receive escalating doses of the allergy serum. You will notice decreased symptom severity as your immune system becomes less sensitive to your allergen.

Places Where Mold May Be Present

Mold is typically present in moist, dark areas, inside and outside the home, where there is organic matter, such as wood, for them to grow on. Look for mold in these locations:

• Poorly vented bathrooms, look around showers and sinks
• Wet basements in corners and any exposed wood or insulation
• Poorly vented laundry rooms
• Around windows
• In kitchens, under the sinks, refrigerators, and dishwashers
• Attics with poor ventilation and roof leaks can accumulate moisture
• Crawlspaces that accumulate moisture
• Air ducts that are not properly maintained
• Wet carpeting
• Along damaged roofs or clogged gutters
• Along exterior wall cracks
• Leaf piles or garden waste
• Wooden decks and fences
• Outdoor furniture

Remove moisture sources, caulk, and check for gaps in walls and cabinets. Clean up spills promptly, improve house ventilation, check the integrity of your windows, roof and gutters, clean appliances that use water, check for condensation, use dehumidifiers, and remove plants to reduce mold in your home.

Types of Mold Allergies

Types of molds causing allergies and human diseases include:^2,3,4

• Alternaria: An outdoor mold found in soil, plants, and decaying vegetation.
• Cladosporium: found on plants, soils, and HVAC systems.
• Aspergillus: found on decaying leaves and compost piles
• Penicillium: found in damp homes.
• Mucor: found in soil, plant surfaces, and decaying leaves.

All mold species have the potential to cause sensitization and allergies, but compared to other environmental allergens, the allergenic potential of each mold species is low.⁴

Mold Allergies vs. Seasonal Allergies

Mold allergens are common anywhere there is moisture, inside and outside the home. Like other indoor allergens, such as dust mites and pet dander, mold allergies can cause symptoms year-round.

Seasonal allergies are caused by outdoor allergens that peak at certain times of the year. Seasonal allergies, like mold allergies, are common. Both seasonal allergies and mold allergies cause similar symptoms. It may be easier to diagnose seasonal allergies than mold allergies based on the time of year in which you have symptoms. Treatment for seasonal and mold allergies is the same and includes reducing exposure, using medications, and considering allergy testing. Unlike seasonal allergens, mold is more likely to cause asthma and allergy symptoms.

Colds and pink eye have symptoms that overlap with allergies, so it is essential to get an accurate diagnosis before starting treatment.

Are Mold Allergies Genetic?

Both environmental factors and genetic predisposition can influence your risk of developing mold allergies. Specific genetic markers have been linked to mold allergies. However, more research is needed to determine whether specific gene variants cause allergies. Your risk of developing allergies increases if one or both of your parents has allergies.

Who Is Most at Risk of a Mold Allergy?

At the highest risk for mold allergies are people:⁴

• Who work or live in warm, moist climates
• With asthma or allergies
• Who with immunosuppression
• With respiratory diseases such as cystic fibrosis
• At the extremes of age
• Who work in construction, agricultural fields or gardening, mold remediation, library archives, breweries or wineries, paper processing, feed production, ventilation/air conditioning maintenance

Can You Develop a Mold Allergy?

Yes, it is possible to develop a mold or other type of allergy later in life. Changes in your environment, immune response, or overall health can increase your sensitivity to allergens.

Can You Outgrow a Mold Allergy?

It is possible to outgrow a mold allergy, but it is uncommon.

When To Consult a Doctor

If you are unsure whether allergies are causing your symptoms or you have more severe allergies or asthma symptoms, consult with an online doctor on the TelegraMD platform. Doctors are on call 24 hours a day to provide an online diagnosis, prescribe appropriate treatment, and provide an individualized treatment plan to combat your allergy symptoms.

Disclaimer

While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.

References

1. Borchers, A.T., Chang, C. & Eric Gershwin, M. Mold and Human Health: a Reality Check. Clinic Rev Allerg Immunol 52, 305–322 (2017). https://doi.org/10.1007/s12016-017-8601-z

2. Portnoy JM, Jara D. Mold allergy revisited. Ann Allergy Asthma Immunol. 2015 Feb;114(2):83-9. doi: 10.1016/j.anai.2014.10.004. PMID: 25624128.

3. Singh, M., & Hays, A. (2016). Indoor and outdoor allergies. Primary Care, 43(3), 451–463. https://doi.org/10.1016/j.pop.2016.04.013

4. Hurraß J, Heinzow B, Aurbach U, Bergmann KC, Bufe A, Buzina W, Cornely OA, Engelhart S, Fischer G, Gabrio T, Heinz W, Herr CEW, Kleine-Tebbe J, Klimek L, Köberle M, Lichtnecker H, Lob-Corzilius T, Merget R, Mülleneisen N, Nowak D, Rabe U, Raulf M, Seidl HP, Steiß JO, Szewszyk R, Thomas P, Valtanen K, Wiesmüller GA. Medical diagnostics for indoor mold exposure. Int J Hyg Environ Health. 2017 Apr;220(2 Pt B):305-328. doi: 10.1016/j.ijheh.2016.11.012. Epub 2016 Dec 5. PMID: 27986496.