ACAAI: Data lacking on toxic mould syndrome

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http://www.medicalpost.com/mpcontent/article.jsp?

content=20051212_193258_5568

ACAAI: Data lacking on toxic mould syndrome

Review of diagnosed cases shows almost all have alternative medical

or psychiatric explanations

By Schieszer

ANAHEIM, CALIF. | The majority of patients who think they have toxic

mould syndrome actually don't. In fact, inhalation toxicity continues

to cause public concern despite a lack of scientific evidence that

supports its existence, say researchers in Oregon.

" Based on our findings, no case definition is possible for so-called

toxic mould syndrome, " said Dr. Emil Bardana, professor of medicine

at Oregon Health and Science University in Portland.

" Fungal contamination of a residence does not necessarily constitute

an abnormal exposure. The presence of fungal allergen sensitivity

proves prior exposure, but not necessarily a symptomatic state.

Because moulds are encountered both indoors and outdoors, it is

almost impossible to determine where the sensitivity arose. "

He said specific toxicity due to inhaled moulds, including the role

of Stachybotrys in building-related illness, has not been

scientifically established by any published study.

Dr. Bardana and his colleagues conducted a retrospective review of 50

individuals who claimed compensation for toxic mould disease. The

researchers found that in all 50 cases there were alternative medical

and/or psychiatric explanations for the claimed illnesses.

Overall, the researchers found only two of the 50 subjects even had

evidence of mould-related allergic disease attributable to their home

or workplace. Dr. Bardana said 17 complained of nonspecific irritant

symptoms that could not be linked to mould exposure. These included

headache, irritability, cognitive impairment and fatigue.

Moulds typically cited as causing psychological or cognitive problems

are Stachybotrys chartarum, Aspergillus, Fusarium, and Penicillium.

Physical symptoms may include sleep deprivation, loss of appetite,

fatigue, headaches, dizziness, vague aches and pains, and respiratory

problems. Psychological and cognitive symptoms include irritability,

panic, anxiety, poor concentration and confusion.

Fungi, including moulds, are spore-producing organisms that comprise

approximately 25% of the Earth's biomass and function as decomposers

of organic material, said Dr. Weber, professor of medicine at

National Jewish Medical and Research Centre in Denver, Colo. He said

only about 80 of the 1.5 million species of fungi are known to be

allergenic.

Dr. Weber, who spoke here at a scientific forum on the health effects

of mould, said the most common fungi found in homes include

Cladosporium, Asper-gillus, Penicillium, Alternaria, basidiospores,

Chaetomium, Periconia and Stachybotry.

" Indoor levels of airborne fungi are generally below outdoor levels

of similar species in a well-constructed home without water damage.

We have found 30% to 70% of recovered indoor spores come from outside

sources, " said Dr. Weber. " There are tons of moulds that we are

exposed to every day in our homes and outside, and the question is

what is an abnormal exposure. "

He said there are no thresholds that have been established for

Cladosporium or Penicillium for causing any specific illnesses. Dr.

Weber said many patients attribute physical and psychological

symptoms they experience to mould exposure when the symptoms are

actually being caused by other factors. He said misinformation by the

media and even physicians may be contributing to this problem.

" There are well-defined problems that people can get into with

(mould) exposures, " said Dr. Weber in an interview. " However, are

mould toxins as big a problem as we think they may be? The problem is

we just don't know. There is not enough information and there are

also not enough good ways of assessing the impact of some of these

toxins on patients. "

It is well-documented that sensitivity to fungi may be prevalent in

asthmatics. Increased outdoor fungal spore counts have been

associated with increased asthma emergency room visits and

hospitalizations. In mould-sensitive patients, immunotherapy has been

found to be effective in several double-blind, placebo-controlled

trials.

" Although there are hundreds of thousands of species of fungi,

allergen extract availability is limited to a relatively small number

of fungi, including the two most prevalent outdoor fungi, Alternaria

and Cladosporium, " said Dr. Harold , professor of medicine at

the National Jewish Medical and Research Centre and University of

Colorado Health Science Centre in Denver.

" Immunotherapy should be limited to those patients with documented

sensitivity to fungus, whose symptoms occur during periods of high

atmospheric exposure to that fungus, and environmental control is not

possible. "