Laboratory Testing for Mold Exposure
Currently, there are no uniformly accepted, valid laboratory tests to diagnose mold exposure in humans. 1
Key Points About Mold Exposure Testing
- There is currently no validated method to test humans for toxigenic mold exposure 1
- No standardized serologic tests exist to assess exposures to mold and other agents associated with damp indoor environments 1
- There are no accepted valid airborne levels of mold that predict adverse health effects 1
- Serum antigen-specific IgG or IgA testing should not be relied upon solely to confirm or rule out the diagnosis of hypersensitivity pneumonitis (HP) due to mold exposure 1
- Antigen-specific inhalation challenge testing and lymphocyte proliferation testing are not recommended to support the diagnosis of HP from mold exposure 1
Environmental Testing Considerations
- Environmental sampling may be useful to identify the source if there is a suspicion of mold (e.g., musty odor) but no visible mold growth 1
- If environmental sampling is done, it should be performed by professionals with expertise in evaluating indoor mold/dampness problems, such as industrial hygienists or indoor environmental quality consultants 1
- Air sampling requires specialized equipment and expertise; an outdoor air sample should be collected simultaneously for comparison 1
- Higher indoor concentrations of mold, predominance of one type, or differences in types found indoors versus outdoors suggest an indoor mold problem 1
Clinical Approach to Suspected Mold Exposure
For patients with allergic symptoms, conventional allergy testing may be appropriate: 2
- Skin prick/puncture tests for mold allergens
- Specific IgE antibody tests for common molds
For immunocompromised patients: 2, 3
- Immediate cessation of mold exposure is the priority
- Radiological, microbiological, serological, and immunological testing may be needed if invasive fungal infection is suspected
For patients with suspected hypersensitivity pneumonitis: 1
- High-resolution CT findings should be integrated with clinical findings, but not used in isolation to make a definite diagnosis
- Clinical improvement with antigen avoidance may support but not confirm the diagnosis
Common Pitfalls to Avoid
- Blood or urine tests for particular mold components or metabolites are not validated for clinical use 2, 3
- Assays to detect mycotoxins and microbial volatile organic compounds have been developed for research but have not been standardized for clinical use 1
- Indoor measurements of mold fungi, microbial volatile organic compounds (MVOC), and/or mycotoxins are generally not indicated as part of the medical evaluation 3
- Testing the environment for specific molds is usually not necessary for small areas of visible mold growth 1
- Relying solely on clinical improvement with medical therapy to confirm a diagnosis of mold-related illness is not recommended 1
When mold exposure is suspected, focus on identifying and remediating the source of moisture that supports mold growth rather than extensive laboratory testing, as this approach addresses the root cause and is more likely to improve health outcomes 4, 2.