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  • Molds are very common indoors where moisture exists in enclosed spaces.

  • Most common indoor molds are Cladosporium, Penicillium, Aspergillus, and Alternaria.

  • People most at risk for health problems include those with allergies, asthma, and underlying immunocompromising conditions.

Molds are commonly present in homes, particularly in the presence of moisture, and patients will commonly seek assessment for whether their illness is due to molds. Well-established health problems due to molds can be considered in three categories: (1) There is the potential for allergy to environmental mold species, which can manifest in the typical manner with allergic symptoms such as rhinitis and eye irritation. Furthermore, in predisposed individuals, exposure to certain molds can trigger asthma or asthmatic attacks. These types of manifestations are reversible with appropriate therapies. More chronic allergic effects can be seen with disorders such as ABPA (see Allergic Forms of Aspergillosis); (2) Susceptible individuals can develop hypersensitivity reactions upon exposure to mold antigens; these include occupational disorders (eg, farmer’s lung and pigeon breeder’s disease) as well as hypersensitivity pneumonitis in response to a large antigenic exposure. Affected patients have fever, lymph node swelling, and pulmonary infiltrates. These disease manifestations are transient and improve with removal of the offending antigen; (3) Invasive mold disease (see Invasive Aspergillosis).

At the present time, there are no data to support that mold exposure can induce immune dysfunction. Similarly, the concept of toxic-mold syndrome or cognitive impairment due to inhalation of mycotoxins has not been validated despite scrutiny by expert panels. The presence of mold in the household is typically easily discernable with visual inspection or detection by odor; if present, predisposing conditions should be corrected by individuals experienced in mold remediation.

Several laboratories offer testing for the evaluation of patients who suspect they have a mold-induced disorder, such as testing homes for mold spores, measuring urinary “mycotoxins,” and performing serum IgG assays to molds. However, these tests should not be obtained as most are not validated and do not provide meaningful results upon which to make therapeutic decisions.

Borchers  AT  et al. Mold and human health: a reality check. Clin Rev Allergy Immunol. 2017;52:305.
[PubMed: 28299723]  
Chang  C  et al. The myth of mycotoxins and mold injury. Clin Rev Allergy Immunol. 2019;57:449.
[PubMed: 31608429]  

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