It is accepted science that molds have the ability to activate our immune system and produce hay-fever-type immediate allergic reactions. Newer research has found that mold has the ability to impair our immune system and provoke chronic inflammation, disturb our hormonal system, cause auto-immunity, and even promote cancer. The research showing that nontoxic molds can cause delayed immune response and that toxins produced by some molds can cause chronic inflammation and illness is not yet widely accepted by the medical community.
Mold as an Allergen?
Since the 1920’s the medical community has accepted the model that substances in the environment, ingested in our food, or injected into a human’s blood can cause immediate hypersensitivity immune response. Immunoglobulin E (IgE) is the culprit and the reaction was coined “atopy”. This led to the creation of skin tests to identify the allergen based on the size of the “wheal and flare” response of the skin. In order to desensitize the immune system from over-reacting to those mediators and causing illness in individuals allergy shots were administered.
Later, a second type of immune response was discovered showing that Immunoglobins (IgE, IgM, IgG, etc.) can bind with proteins from viruses and bacteria. These “immune complexes” provoke the formation of the complement cascade to occur over hours and days to protect us from these pathogens (type 2).
We also have reactions (type 3), which occur when IgG binds to a foreign substance and causes an irritation inflammatory complex to develop over hours or days; providing protection from toxins.
Lastly, we have T-cells in our immune system that become sensitized by a bacteria invading the body and cause an inflammatory response that may be seen at 48 to 72 hours after exposure (the Tb-skin test is an example of this reaction).
For a long period of time, allergists attributed delayed hypersensitivity (Type 2-4) reactions to fungi/mold as only due to toxic mold, and the immediate IgE mediated reactions (skin test) to non-toxic or allergic fungi. This led to the belief that common molds can stimulate the immune system only through immediate, IgE, allergy response.
Dr. Ritchie Shoemaker, MD, and others, observed somewhat controversially, that mold activated the complement cascade system stimulating the late and delayed immune reactions. This implies that nontoxic molds can trigger complement cascade and that the problem is broader than previously accepted, thus the controversy.
What are Molds
Molds are fungi that grow best in warm, damp, and humid conditions. There are tens of thousands of species that spread and reproduce by making spores that can survive harsh environmental conditions. According to the Centers for Disease Control (CDC), the most common indoor molds are of the Cladosporium, Penicillium, Alternaria, and Aspergillus genera. Typically, any area with a relative humidity of greater than 80% in the presence of metabolizable organic materials supports mold growth. A relative humidity of more than 90% is ideal for proliferation.
Fungi are always present in our environment. They live outdoors as well as in our homes and we breathe in their spores. They can live on food, especially grains and corn, and any food that is stored for a long period of time. They are used in the making of bread and wine. In fact, blue cheese is made with Penicillium and soy sauce is made with Aspergillus. Other molds can be found in and outside of the human body. Candida lives in the digestive tract and Aspergillus and candida can be found in the ear canal. The most common mold found in the stool of humans is candida, but sometimes we find geotrichum from Camember cheese and Rhodotorula species.
How Does Mold Make Us Sick?
Mold spores are breathed in or ingested through food. It is accepted by the medical community that mold causes an allergic reaction and once the person removed from the exposure the response will resolve. Other problems include respiratory and/or immune system responses such as respiratory symptoms, respiratory infections, exacerbation of asthma, and chronic sinusitis. Some fungi make toxins. When mold spores are present in abnormally high quantities, they can present especially toxic effects to humans after prolonged exposure, including allergic reactions or poisoning by mycotoxins or causing fungal infection (mycosis).
Dr. Ritchie Shoemaker and Dr. Andrew Campbell have published books and journal articles on mold toxicity. In a comprehensive review published in 2004, Dr. Campbell evaluated the research on the physiological effects of mold toxins that go beyond the typical immune response. The research covered symptoms reported by people living or working in water-damaged buildings. They compared their symptoms with an “unexposed” control population. The top symptoms were mostly neurologic, including:
- Memory Problems
- Slurred Speech
- Weak Voice
- Watery Eyes
In addition to the neurologic, other symptoms, mold illness can cause include:
- Muscle cramps
- Unusual pain
- Light sensitivity
- Red eyes
- Blurred vision
- Shortness of breath
- Abdominal pain
- Joint pain
- Morning stiffness
- Skin sensitivity
- Mood swings
- Appetite changes
- Increased sweating
- Dysregulation problems
- Excessive thirst
- Increased urination
- Static shocks
- Metallic taste
Multi-system symptoms are known to be caused by auto-immune conditions and/or environmentally acquired illnesses such as Lyme disease or heavy metal toxicity. Through Dr. Shoemaker and Campbell’s work we now know that mold can produce the same in animals and humans. In addition to these typical symptoms, Dr. Neil Nathan in his book, Toxic, identified some specific symptoms of mold illness that can help distinguish it if present. These symptoms include electric shock sensations, ice pick-like pains, and vibrating or pulsating sensations running up and down the spine.
In his groundbreaking book, Mold Warriors, Dr. Ritchie Shoemaker taught us that some of these toxins can remain in the body and be difficult to excrete and destroy. These toxins can compromise the body’s ability to detox and they can accumulate, sometimes causing symptoms to show up after repeated exposure or not until another illness, such as Lyme disease, adds to the toxic load.
In about 75% of the population the immune system recognizes the toxins and destroys them. In about 25% of the population their immune system does not recognize the toxins and therefore is unable to destroy them. These people can become very ill from exposure to mycotoxins.
In addition to exposure to mold, people can fall ill from being within damp buildings, not only from mold and mycotoxins, but because these environments also produce bacteria and help release volatile organic compounds.
How Are We Exposed to Mold?
Most people that are found to be ill from the effect of mold toxins had no idea prior to diagnosis that their home or office contained mold. Many have found mold that developed over time from leaky water pipes behind showers, dishwashers and refrigerators. Other areas of exposure are from leaky roofs, windows, and doors. Obstructed gutters can cause overflow of water down fascia into an attic or inside cladding. Siding can be a source of moisture from wind driven water, nail holes and cracks, and leaky and moisture-prone basements and crawl spaces are common.
Many terms have been used to describe the phenomenon of mold illness from inside buildings, such as sick building syndrome (SBS). In 2009, the World Health Organization (WHO) published a comprehensive guideline, “Indoor Air Quality: Dampness and Mould”. In this 248-page report, the WHO estimated that 10% to 50% of indoor environments in Europe, North America, Australia, India, and Japan have clinically significant levels of mold.
Environmental Toxins and Mold Illness
Although the research is limited, there is compelling evidence that mold illness extends beyond an allergic reaction in some humans and is a cause of debilitating, chronic illness. Environmentally acquired illnesses, such as mold illness, are on the rise due to the rising number of toxins in our environment. Although controversial, there are a group of health practitioners devoted to research, testing, treatment, and education on the environmentally acquired illnesses. Today there are more and more patients experiencing complex, multi-system symptoms. The International Society of Environmentally Acquired Illnesses is one group helping to get answers for this very sick patient population.
Dr. Clark is a member of the International Society for Environmentally Acquired Illness (ISEAI), a 501(c)(3) nonprofit professional medical society that aims to raise awareness of the environmental causes of inflammatory illnesses.