Mold is a common eczema trigger. Mold has been shown to trigger atopic dermatitis-related inflammation through the cytokines associated with atopic allergies. Mold can also have a direct irritant effect or a toxic effect on the immune system through exposure to the skin and the respiratory tract (nose, throat, lungs).
Molds grow both outdoors and indoors, and while indoor mold more frequently triggers eczema flares, outdoor molds can trigger a flare, as well. Outdoor molds are on trees and grass in the spring, summer and fall. Cutting grass sends mold into the air, but at other times, outdoor molds are easy to avoid (don’t roll in grass, and don’t physically contact trees or exercise under them). Most people with allergies have a couple of tree specific mold allergies they must avoid, and other trees are safe for them to be under.
Pollens, by contrast, are the particles released by plants from their fertilization cycles. They are very seasonal and very hard to avoid. In their season, pollens are everywhere except in air conditioned buildings and homes with well maintained A/C filters and air purifiers. Pollens are more likely to flare allergic rhinitis (runny nose, watery eyes) than eczema, but they can contribute to itchy eyelids and this can lead to a flare of rubbing and scratching. Rubbing and scratching alone can flare eczema more extensively.
What is mold, though? When is it more likely to trigger atopic dermatitis? What happens if you find mold in your home? Are all molds the same, and is so-called “black mold” as dangerous as many claim it is? How do you treat eczema after mold exposure?
A Kingdom Apart
We tend to speak about mold as a singular entity, but there are hundreds of thousands of known mold species, each having distinct properties. Molds are multicellular fungi. Unlike mushrooms, their fellow citizens of the fungus kingdom, molds do not produce pronounced fruiting bodies and have a “flat” appearance. They can grow on any organic material, including clothing, leather, and wood (“mildew” is visible mold growth). Their preferred environment is damp and dark; they can often be found in basements and bathrooms in the home, as well as places where plumbing leaks.
Most molds can reproduce asexually through the formation and release of spores, tiny particles made to disperse the mold’s genetic material. These spores range in size from two to ten microns (a micron is one millionth of a meter). A single mold growth will release thousands of spores at a time.
When they’re dispersed, they travel via air current, water, or insect express–sometimes at great distances. If the surface they settle on is advantageous, they’ll form the growth of a mold colony. The allergenic properties of mold are caused mostly by these microscopic spores.
Are All Molds Bad?
Relatively few molds cause problems for us, and not everyone is equally sensitive to those. Cladosporium, Aspergillus, and Penicillium are the top three fungi implicated in the development of atopic dermatitis.
While Cladosporium is primarily found outdoors, it is a hearty fungus that can survive in extreme conditions; it has no problem at all making itself at home indoors. This mold comes in an array of colors; it can be an olive drab shade, or it can be beige, black-brown, brown, or gray. Forty-two percent of children under four had allergic reactions to Cladosporium in one study!
Aspergillus appears in clusters of small, circular medallions that can be a pale verdigris, dark brown, or very dark grey. It has a fondness for houseplants and their soil; if you purchased houseplants to improve indoor air quality, you should check foliage and soil to be sure you aren’t doing the opposite. Like Penicillium, it loves damp, dark places.
Aspergillus molds are everywhere in small amounts. When people are exposed to higher concentrations, it contributes to allergies and itching that can trigger eczema. Immunosuppressed people should avoid working with soil and plants, leaves, compost, and mulch. Rarely, Aspergillus can infect the lungs with a fatal infection in Immunocompromised individuals. There are other fungi in soil and wet leaves that can cause serious infections in the immunocompromised, entering through the lungs or a skin wound.
Aspergillus can be black, but it doesn’t grow on cellulose (the paper part of drywall) like Stachybotrys chartarum does. S. chartarum is considered potentially toxic (releasing toxins into the air that make people feel ill), as well as causing all the allergic problems of molds. Be careful of unscrupulous people who over-diagnose and overcharge for this problem. Take a photo and talk to experienced people at Lowes or Home Depot about dealing with early mold on cellulose, not the new hire.
Penicillium is the mold we will likely find on a forgotten slice of bread. It begins as a fuzzy-looking white patch that becomes bluish green, verdigris, yellow or pinkish–rather like a textured bruise. Penicillium loves damp walls, upholstery, carpet and dust. Penicillium is highly allergenic (it is worthwhile to note that those allergic to penicillins, a class of antibiotics derived from compounds produced by Penicillium, are not automatically allergic to Penicillium molds in the environment).
Alternaria is another mold that the Allergist often skin tests for. It’s mostly outside around plants and soil with dampness. It can contribute to allergic rhinitis.
Spores can be brought in from the outdoors through heating and cooling systems, as well as on clothing. When Cladosporium, for example, is at its peak levels outside, its indoor levels are typically higher, as well.
How Does Mold Trigger Eczema?
The microscopic nature of mold spores allows them to spread over diffuse areas and slip through barriers that would keep out larger particles. When someone sensitive to mold comes into contact with these spores, either through touch or by inhalation, the immune system goes into overdrive.
Acting rapidly to expel the irritating particles, mast cells and basophils flood the affected system with histamine. The blood vessels dilate and become more permeable. Fluid swells the skin. People with eczema will experience swelling, redness, and itching. If the person is not removed from the trigger, the flare can worsen, with oozing and cracking.
You can suspect mold as a trigger if you’ve eliminated other potential triggers in your home (e.g., pet dander, dust), and your symptoms improve after spending several days away.
Preventing and Addressing Mold Growth
The abundance of molds in our environment, their ability to reproduce prolifically, and the advantageous conditions supplied indoors complicate the identification and elimination of mold from indoor environments. Molds become a problem in the home before they’re ever visible. By the time you see the tell-tale blotches, the mold is capable of forming numerous sporangiophores, each containing thousands of spores awaiting release. This means that visible mold should be taken seriously and removed promptly, especially in places occupied by someone with mold allergies or compromised immunity.
The best cure is prevention, so checking for plumbing leaks in walls, under sinks, and beneath the home is important. If the home is humid, dehumidifiers are useful, especially in bedrooms, basements, and closets. Bathrooms and kitchens should be cleaned regularly to address residual dampness from baths and cooking.
Beds should be covered in protective mattress pads that are washed regularly, especially in the months mold spores are at peak numbers (from July-November). Pillows should be covered, as well, with the covers washed regularly.
An air purifier made by a reputable company can help trap airborne particles, including mold spores, and reduce their presence in the air. Air purifiers are also recommended for people with respiratory allergies. Vacuuming regularly with a HEPA-filter equipped vacuum cleaner also helps; be sure to clean and replace filters as needed. Ensure that the space is well-ventilated.
If you do discover mold despite your best efforts (and you are seriously outnumbered), then assess the damage. If the mold affects a small area, and the conditions that led to the mold have been addressed, it can be cleaned by the residents. People with mold-triggered eczema, asthma, or allergies should not be doing the cleaning, ideally.
Hard surfaces can be scrubbed with detergent and water, then sprayed with a bleach solution (1 cup bleach per 1 gallon water). The area should be well-ventilated as you work, and you should ensure that it dries thoroughly after cleaning. Mold can be cleaned from wood with warm water and dish detergent.
If the damage is more extensive, expanding into your home’s structure, consider calling mold remediation specialists. Be wary if they demand tests to identify the mold or if they have information about the dangers of black mold on their websites.
If you suspect that mold is growing in your heating or cooling unit, do not run the unit until it can be thoroughly checked over and cleared of any mold growth. Most people will need the help of a professional here.
What About the Dreaded “Black Mold?”
Over the last 20 years or so, concerns about “black mold” have become highly publicized. A mold’s toxicity is unrelated to color, and many different molds can be black. Most of the time, discussions of black mold center around S. chartarum, which can produce toxins associated with illness. If you suspect that you have a growth of S. chartarum, as previously noted, photograph the mold and take the photo to a knowledgeable associate at Lowe’s or Home Depot. Concerns about health effects of mold growth should be addressed promptly with your physician.
Mold removal of any kind should not be undertaken by those with mold allergies or compromised immune systems. There are competent mold removal specialists, often working with general cleaning contractors, who can assist you.
As we noted before, be wary of people overcharging for black mold removal. Similarly, be cautious about laboratories offering blood tests for black mold mycotoxins–there is no way to identify the presence of mycotoxins in the blood. This is a concern for your physician, who can do blood tests for signs of mold allergy–usually at far less cost than independent laboratories charge.
Any mold growth (regardless of color) should be taken seriously, especially if it seems to correlate with sickness or allergy symptoms among household members.
How Is Mold-Related Dermatitis Treated?
The treatment should consist foremost in removing the patient from the mold-infested area. Antihistamines such as ZyrtecⓇ and ClaritinⓇ can help stop the itching that occurs when mold triggers an eczema flare.
An over-the-counter topical steroid treatment such as SmartLotionⓇ is an excellent choice to address the redness and itching, as well. Containing 0.75% Hydrocortisone USP, it offers considerable safety when treating redness, swelling, and itching involving the face and eyelids. Strong prescription steroids have less safety around the eyelids. You really need to look for the best eczema cream possible to treat flares.
SmartLotionⓇ can be used for short periods for triggered eczema flares involving the eyelids. When used repeatedly for chronic recurring dermatitis, there should be supervision by a Dermatology provider, and yearly checkups with the Eye doctor. When used properly with supervision, eczema sufferers can be confident they greatly reduce the risk of any side effects, and will not experience topical steroid withdrawal (TSW).
Antihistamines and cold compresses should also be used to reduce symptoms and shorten the flare of mold-triggered eczema. Calcineurin inhibitor Pimecrolimus cream is often prescribed by Dermatology providers as a non-steroid treatment for eyelid eczema. By itself, Elidel® cream does not work fast. It works best after initial control and improvement from corticosteroids and cold compresses.
SmartLotion® also contains a superior strategy for barrier repair and microbiome balancing from prebiotic effects. These contribute to fast results with less Hydrocortisone. Mold or pollen from recent exposure should be gently cleansed away. With cold compressing, SmartLotion can be applied as a thin disappearing layer to skin 2-3 times per day until symptoms improve. Seek an evaluation for a proper diagnosis from a Dermatology provider.
- Zula Elwood