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HYPERSENSITIVITY TO MOLD
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 A homeowner
experienced congestion and respiratory difficulties after moving into her new
residence. It was discovered that many
items in her basement supported fungal growth due to elevated relative
humidity. Out of curiosity, she went to
an allergist to test for mold sensitivities.
The tests came back negative.
Yet, when she cleaned the mold from the basement and corrected the
humidity problems, her symptoms went away.
The homeowner then went to another allergy clinic for a second
opinion. Again, she was not diagnosed
with allergies. How is this
possible? Because the homeowner was not
tested for both Type I and Type IV hypersensitivities to mold.
When a patient is
tested for allergies, he or she is actually being tested for Type I
hypersensitivities, also termed "immediate hypersensitivity". Allergists are able to screen for the
presence of Type I reactions by doing skin prick tests and observing an
immediate redness and swelling around the area where the test was
administered. This is called a "wheal
and flare" reaction.
In our experience, it
is important to test for Type IV hypersensitivities, in addition to the
standard Type I (allergy) test. A Type
IV hypersensitivity, or delayed-type hypersensitivity (DTH) reaction, occurs
along a different immune pathway and typically requires 48-72 hours to
mature. Familiar DTH reactions include
contact dermatitis (e.g., poison ivy, latex) and hypersensitivity pneumonitis
(farmer's lung). Anecdotal evidence
suggests that some people who experience DTH reactions also suffer from
fatigue, depression, respiratory distress and other seemingly unrelated health
symptoms.
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WHY THE DELAYED REACTION?
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 We all have immune
system cells in our bodies that are called T-regulatory (T-reg) cells. These cells act to limit or control immune
system reactions to harmless compounds, such as food proteins and many types of
mold. Without T-reg cells, our bodies
would regard many commonly encountered compounds as threats to our health, causing
our immune systems to respond. For
unknown reasons, some people have T-reg cells that do not recognize
certain molds as benign. As a result,
these people may develop DTH responses to commonly encountered molds, such as
those associated with water-damaged buildings. |
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CONCLUSIONS
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If a person suffering
from DTH (Type IV) reactions is only tested for immediate (Type I) reactions,
they will be misdiagnosed as having no reaction to mold, and therefore will not
be appropriately treated for their symptoms.
For those who are experiencing health effects that may be related to
water-damaged buildings or mold exposure, we've found that it's important for
their healthcare professional to test for both Type I and Type IV
hypersensitivity. |
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 For more information about this topic or additional IAQ concerns, please contact Cassidy Kuchenbecker at (414) 257-9590 or CLK@MichaelsEngineering.com. |
| Cassidy
Kuchenbecker
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