Repeated exposure to mold can trigger allergies and immune issues.

We write extensively about food allergies and sensitivities, but today we’re focusing on environmental allergens- especially mold. Mold as an allergen is generally classified into the categories of indoor molds, and outdoor molds. Outdoor molds are at their peak right now and into the fall. Mold thrives on moist conditions and decaying matter. With summer rains, heat, and humidity outdoor molds thrive at this time of year. In the fall, damp falling leaves and still humid conditions will also cause a steady level of mold growth and spore release. Indoor molds can also be high in the summertime. Mold likes moisture and warmer temperatures. While air conditioning will suppress mold by lowering the humidity and warmth of a building, homes might be more susceptible than other structures to indoor mold growth even with air conditioning because of maintenance, filtering, failure, or mold growth in the unit or in a dehumidifier.

Why should practitioners concern themselves with patients’ home maintenance? Well, we’re not suggesting you become their home repair advisors, but there are two reasons why it’s relevant to have that information. The first is that it’s notoriously difficult to track specific mold exposure events, but it is possible to identify sources of continuous mold exposure. One-time exposure to mold sources is unlikely to trigger a mold allergy, but repeated exposure is potentially likely to cause an allergy to develop. It often takes less repeated exposures than you might think to create a mold allergy, depending upon a person’s genetics, type of mold, and intensity of exposure. Indoor mold exposure in particular can trigger mold allergies and worsen the effects of asthma and other lung conditions, and merely the visible presence of dampness or mold in the home can correlate to symptoms: “Several ECRHS studies have shown that visible indoor mold or dampness assessed by questionnaires were associated with increased prevalence of asthma symptoms, diagnosed asthma, and bronchial hyper-responsiveness. In particular, indoor mold exposure in asthmatics has a severe impact on respiratory symptoms, i.e., exacerbation and aggravation.” (Kespohl, et al, Allergol Select. 2022; 6) Outdoor allergies can also be triggered by repetitive activities that a patient may not realize risk mold exposure. Using (especially turning) a compost heap, gardening (especially mulching, planting, and disturbing leaf litter), and mowing the lawn are all activities that can eventually trigger mold allergies in some, and worsen bronchial conditions in others. Surveying patients with allergy or bronchial symptoms, or existing asthma patients is the first step in identifying and treating mold allergies.

The second step is testing for mold allergies through serum. Alternative testing sometimes isn’t available, or not recommended “There are few commercial test allergens available to perform skin tests for suspected mold allergy, and even less mold extracts for provocation tests. To detect toxic/irritant effects, it is necessary to know the responsible mold species and to be able to quantify the exposure, which is usually not possible.” (same source). Serum testing is the chosen method to identify mold allergies, because of its availability, its accuracy, and the ability to test for specific mold species easily “Since skin prick test for mold allergens are becoming increasingly rare, serological tests are the only alternative. In a previous study, it was shown that IgE testing with mx1 mold mixture is a valid tool for screening for potential mold sensitization” (same source).

The Precision Point Diagnostics Airborne Allergy panel is an IgE-mediated serum test of 85 common airborne allergens including pet dander, mold, dust mites, grasses, crops, trees, and weeds. Because those especially susceptible to mold allergies and their effects are often also affected by other environmental allergens, it’s convenient and more comprehensive to begin with a broader panel such as this one. The test also features an expanded mold panel, measuring 18 different mold organisms such as Aspergillus fumigatus, Cladosporium cladosporioides, Fusarium roseum, and Penicillium. Unlike tests that utilize mold mixes, these mold species are separately tested and identified on the report, making it easy to identify specific areas of concern and begin intervention and remediation. Identifying a mold allergy might also explain the underlying causes of other bronchial and inflammatory issues.

After a mold allergy or a condition exacerbated by mold is identified by the panel, follow-up testing could be ordered if desired, but at this point remediation is in order. This is the second reason why surveying the patient about home conditions and outdoor habits is necessary. Remediation doesn’t have to mean ripping out walls, as suggested by the companies that offer the services but inspecting the home for water leaks, the roof, the gradient around the house that might allow ingress, sump pumps, air conditioner units, etc. It also means discussing habits- how much do they run the air conditioner? Keep the windows open? What’s the humidity in the house? Do they garden, or mow? Spend a lot of time outdoors? Changing those habits and making sure the house is in good repair can make a huge difference in exacerbating asthma and allergies according to the Asthma and Allergy Foundation of America.

Why should we take mold allergies and exposure so seriously? Aside from the effects of mold allergies themselves, “Next to IgE-mediated pathomechanisms, mold exposure can also induce inflammatory health effects.” (same source). Accepted mechanisms of impact for mold exposure include allergy, infection, and toxicity. A recent study found that innate immune activation may be a separate mechanism of impact. “Our data document for the first time that exposure to known quantities of both toxic and nontoxic mold spores activated a central neural immune response with concomitant cognitive and emotional dysfunction. In addition, we identified a mechanism, innate immune activation, which aptly explains how mold exposure may cause such a diverse array of problems. The extent of the contribution of mold exposure to neural and behavioral dysfunction in humans under ecologically relevant conditions remains to be determined. However, mold exposure, both toxic and nontoxic, must be considered another factor, like pesticide exposure or smoking, that can add to an individual’s burden of inflammation with possible serious consequences for health and behavior.” (Harding, et al, Brain Behav Immun. 2020 Jul; 87). If this is borne out by further research, then it means that mold exposure, even seemingly innocuous exposure, if repeated, may deeply impact a person’s health. 

Combining environmental allergen testing with a separate mold panel, like that from Precision Point Diagnostics, and collecting patient responses regarding outdoor activities and indoor conditions can act as surveillance for potential allergic, immunological, and bronchial problems ahead, as well as being a predictor of some origins of asthma.