Toxic and other non-IgE-mediated effects of fungal exposures

Abstract

There are more than 100000 recognized species of fungi, comprising 25% of the biomass of the earth. Allergic, IgE-induced, manifestations of airborne fungi are common, whereas non-IgE manifestations are rare. Recently, much focus has been placed on the non-IgE-mediated effects of various molds, including hypersensitivity pneumonitis, infectious disease, and mycotoxicoses. Hypersensitivity pneumonitis is a clinical syndrome associated with systemic and interstitial lung disease that occurs in susceptible individuals following fungal inhalation. Most fungi are not pathogenic to man; however, certain fungi are capable of infecting immunocompetent individuals. Although mycotoxins and exposure to mycotoxins ("toxic mold syndrome") are implicated in causing numerous, nonspecific, systemic symptoms, currently, there is no scientific evidence to support the allegation that human health is affected by inhaled mycotoxins. However, if mold is discovered in a home, school, or office setting, the source should be investigated and appropriate remediation undertaken to minimize structural damage and potential allergic sensitization.

Mold and Human Health: Separating the Wheat from the Chaff

“…Nevertheless, these and other questionable studies led the worldwide public and media to be convinced of the unproven danger caused by Stachybotrys and other molds. Accordingly, "toxic mold syndrome" (TMS) was coined by the media to refer to a wide range of nonspecific symptoms in individuals exposed to mold [78]. Similar to SBS, these symptoms (Table 3) included respiratory (rhinorrhea, epistaxis, cough, and shortness of breath), neurological (headache, focal weakness and memory loss), gastrointestinal (nausea, vomiting, and diarrhea), and constitutional (generalized weakness and mood variations) complaints [78], as represented by a 2005 study on 65 individuals, self-reported to have TMS [79].…”

“…Accordingly, "toxic mold syndrome" (TMS) was coined by the media to refer to a wide range of nonspecific symptoms in individuals exposed to mold [78]. Similar to SBS, these symptoms (Table 3) included respiratory (rhinorrhea, epistaxis, cough, and shortness of breath), neurological (headache, focal weakness and memory loss), gastrointestinal (nausea, vomiting, and diarrhea), and constitutional (generalized weakness and mood variations) complaints [78], as represented by a 2005 study on 65 individuals, self-reported to have TMS [79]. This study concluded that a majority of the symptoms were possibly due to allergic reactions to mold in the environment and proposed the possibility of somatization and secondary gain (either emotional or financial).…”

Mycotoxins

“…81 Of the four types of reactions, Ig -E mediated hypersensitivity reactions are the most common. The mechanisms of disease following these exposures include allergy, infection, and toxicity.…”

“…53 This fungus is not pathogenic, and Stachybotrys species prefer stems of woody plants with soil acting as a reservoir. 81 Stachybotrys chartarum (S. atra) frequently is associated with the trichothecenes compounds, satratoxin H, and to a lesser extent with satratoxin G. About one -third of S. chartarum strains are capable of producing mycotoxins, whereas most strains of Stachybotrys chartarum produce spirocyclic compounds. The fungus can survive over winter and the spores may be viable for many years.…”

Mold Hysteria: Origin of the Hoax

“…Toxic mold syndrome caught the attention of the media and the public after an association between black mold accumulation and perceived occupant symptoms was observed (Nordness et al 2003). The visible mold in question turned out to be a fungi belonging to the genus Stachybotrys, which is a mold that causes a black colored build up of spores on various substrates.…”