What tests are used to diagnose mold exposure?

Tests for Mold Exposure

There are no validated laboratory tests to diagnose mold exposure in humans, and environmental mold testing is not recommended as part of routine medical evaluation. 1

Key Evidence Against Routine Testing

The American Academy of Pediatrics explicitly states that:

• No standardized serologic tests exist to reliably assess exposures to mold and other agents associated with damp indoor environments 1
• There is currently no validated method to test humans for toxigenic mold exposure 1, 2
• No accepted valid airborne levels of mold predict adverse health effects 1, 2
• Assays to detect mycotoxins and microbial volatile organic compounds in blood have been developed for research purposes but are not standardized for clinical use 3, 2

Risk-Stratified Diagnostic Approach

For Immunocompetent Patients with Allergic Symptoms

If the patient has evidence of atopy (allergic rhinitis, asthma, eczema), consider:

• Skin prick testing for mold allergens 3, 4
• Mold-specific IgE antibody testing 3, 5

These tests identify IgE-mediated allergic responses to mold, which are the most common health effects. 4 In one study, 53% of mold-exposed patients had positive skin reactions to molds. 4

For Immunocompromised Patients (Absolute Priority)

Immediate cessation of mold exposure is the absolute priority. 3, 5 Then proceed with:

• Chest CT scan (superior to plain radiography for suspected invasive pulmonary aspergillosis) 1, 3, 5
• Serum galactomannan antigen testing for Aspergillus species (accurate in hematologic malignancy and HSCT patients) 1, 3, 5
• Serum (1→3)-β-D-glucan (not specific for Aspergillus but useful in high-risk patients) 1
• Bronchoscopy with bronchoalveolar lavage (BAL) for culture and galactomannan testing 1
• Microbiological cultures from respiratory specimens or tissue biopsies 3, 5
• Immunological evaluation of immune function 3, 5

Note that galactomannan is not recommended for routine screening in solid organ transplant recipients or patients with chronic granulomatous disease. 1

For Suspected Hypersensitivity Pneumonitis

• High-resolution CT (HRCT) looking for centrilobular ground-glass nodules, mosaic attenuation, air-trapping, and three-density sign 3
• Do NOT rely solely on serum antigen-specific IgG or IgA testing to confirm or rule out the diagnosis 3, 2
• Do NOT perform antigen-specific inhalation challenge testing or lymphocyte proliferation testing 2
• HRCT findings must be integrated with clinical findings, not used in isolation 3, 2

Essential Clinical History Elements

Focus on these specific details rather than generic history-taking: 5

• Visible mold growth (discolored patches, cottony or speckled growth on walls/furniture) 1
• Water damage or flooding in home or workplace 1
• Musty or earthy odors in particular areas 1
• Timing of symptoms relative to exposure (improvement away from environment) 5
• Immune status (immunosuppression, chemotherapy, transplant, HIV/AIDS, chronic granulomatous disease) 3, 5
• Atopic history (asthma, allergic rhinitis, eczema) 5
• Occupational and hobby exposures (gardening, mulch spreading, construction work) 1

Critical Pitfalls to Avoid

Do NOT Order These Tests:

• Mycotoxin testing in blood or urine - not validated for clinical use 3, 2, 5
• Environmental mold testing as part of medical evaluation - usually not necessary 1, 2, 5
• Serum antibody testing for hypersensitivity pneumonitis as a sole diagnostic tool 3, 2
• Routine Candida antibody/antigen testing in hematology-oncology patients 5

Environmental Testing Considerations (If Performed):

If environmental sampling is deemed necessary (e.g., musty odor but no visible mold), it should be:

• Performed by professionals with expertise (industrial hygienists, indoor environmental quality consultants) 2
• Conducted with specialized equipment including simultaneous outdoor air sampling for comparison 2
• Interpreted cautiously: higher indoor concentrations, predominance of one type, or differences from outdoor samples suggest an indoor problem 2

When Environmental Remediation Takes Priority Over Testing

For areas of visible mold growth less than 10 square feet, testing the environment for specific molds is usually not necessary - proceed directly to cleanup. 1, 2 Prompt cleaning within 24 hours of water damage prevents mold growth. 1