Environmental illness, mold colonization of the nasal passages, gut, body, and nasal microbiology
An educational overview of multiple-antibiotic-resistant coagulase-negative Staphylococci, suspected fungal or mold colonization of the nasal passages and sinuses, gut, and elsewhere in the body, how nasal testing differs from mycotoxin testing, and how disputed mold/CIRS theories should be discussed with qualified clinicians.
Patients often encounter MARCoNS during mold/CIRS workups, but the test itself is a bacterial culture question. It should not be treated as proof of mold colonization or proof that a building is unsafe.
MARCoNS stands for multiple-antibiotic-resistant coagulase-negative Staphylococci. Coagulase-negative Staphylococci are a group of related bacteria that commonly live on skin and mucous membranes. A MARCoNS report usually means that a nasal culture grew coagulase-negative Staphylococci with resistance to more than one antimicrobial agent.
Colonization means bacteria are present and growing at a body site without necessarily invading tissue or causing acute infection. Active infection is more likely when there is compatible inflammation, worsening local symptoms, fever, purulent drainage, tissue damage, immune compromise, or imaging/exam findings that support sinusitis or another infection.
A positive culture may matter in a CIRS-informed practice, but it is not a stand-alone diagnosis. Coagulase-negative Staphylococci can be normal commensals, contaminants, colonizers, or opportunistic pathogens depending on the patient, specimen quality, symptoms, immune status, and clinician exam.
These tests are often discussed together in complex chronic illness care, but they do not measure the same thing and they cannot be substituted for one another.
| Test | What it looks for | What it cannot prove by itself |
|---|---|---|
| MARCoNS nasal culture | A deep nasal swab is cultured for bacteria, especially coagulase-negative Staphylococci. If bacteria grow, the lab can identify the organism and report whether it meets that lab's MARCoNS resistance definition. | It does not diagnose mold illness, fungal sinusitis, CIRS, mycotoxin illness, or the location of any fungal colonization. |
| Antibiotic-susceptibility testing | The cultured bacteria are exposed to antimicrobial agents in the lab. Results are usually reported as susceptible, intermediate, or resistant and can guide a prescriber if treatment is clinically appropriate. | It does not prove the bacteria are causing symptoms, and it does not mean every positive culture should be treated. |
| Fungal culture | A sinus, nasal, sputum, tissue, or environmental specimen is cultured to see whether yeast or mold grows. Growth can sometimes help identify a fungal organism. | Culture can miss fungi, and a positive result may represent colonization, contamination, allergy-related disease, or infection depending on the clinical setting. |
| Fungal PCR or sequencing | Molecular testing looks for fungal DNA. In fungal chronic rhinosinusitis studies, PCR may detect organisms when culture is negative. | DNA detection does not necessarily prove living fungus, tissue invasion, or that a detected organism is the cause of symptoms. |
| Mycotoxin testing | Different tests attempt to measure toxins, toxin metabolites, or immune responses associated with mycotoxins. Urine mycotoxin testing and antibody-based approaches are interpreted differently by different clinicians. | It does not locate mold in the nasal passages, sinuses, gut, tissues, home, workplace, or belongings. Clinical validity and interpretation remain debated, and results should not be used as a stand-alone diagnosis. |
Some CIRS-informed clinicians view MARCoNS as a persistent sinonasal bacterial colonization that may interact with neuroimmune markers such as melanocyte-stimulating hormone. This is a proposed clinical framework, not settled medical consensus.
In Shoemaker-style CIRS care, MARCoNS is often discussed after exposure control, visual contrast sensitivity screening, inflammatory biomarkers, and binder therapy. The theory is that some mold- or biotoxin-affected patients may have impaired mucosal immune regulation that allows resistant nasal bacteria to persist.
A 2026 retrospective Frontiers in Endocrinology cohort reported that patients who became MARCoNS-negative at follow-up had higher circulating alpha-MSH trajectories than those who remained positive. The authors called for prospective study, which means the finding is hypothesis-generating rather than definitive proof.
Patients may report nasal congestion, postnasal drip, sinus pressure, throat irritation, headaches, smell changes, fatigue, brain fog, sleep disruption, mood changes, dizziness, or pain flares. These symptoms are nonspecific and can also come from allergy, viral illness, bacterial sinusitis, migraine, asthma, MCAS, reflux, sleep problems, medication effects, or other conditions.
Mainstream sinus care usually focuses on symptom duration, nasal endoscopy, imaging when indicated, allergy evaluation, immune status, and evidence of bacterial or fungal rhinosinusitis. LADA encourages patients to bring MARCoNS results into a broader differential diagnosis rather than assuming one result explains every symptom.
Dr. Andrew W. Campbell has published and spoken about chronic illness associated with mold and mycotoxin exposure. LADA is describing his work for education and is not endorsing a treatment protocol.
Dr. Campbell's materials describe serum IgG and IgE antibody testing related to mycotoxins. These tests use blood serum, not nasal IgG. They do not identify where a fungus might be colonizing, and they do not show whether the nasal passages, sinuses, gut, lungs, skin, bloodstream, home, workplace, or belongings are the source of exposure.
His clinical view is that some patients can remain ill after leaving a water-damaged environment, especially when immune reactivity, fungal or mycotoxin-related illness, or ongoing colonization in the nasal passages, sinuses, gut, or elsewhere in the body is suspected. This interpretation is not universally accepted as established medical consensus.
Dr. Campbell's public materials and case examples discuss oral itraconazole treatment, sometimes for prolonged courses such as six months or longer, with repeat laboratory testing and clinical monitoring during treatment. This should be understood as his reported clinical approach, not a general LADA recommendation.
Long-term itraconazole can cause serious liver injury, can worsen or contribute to heart failure in susceptible patients, and has major drug-interaction risks through CYP3A4. Prescription antifungal treatment should only be undertaken under the supervision of a qualified prescriber who can review cardiac risk, liver testing, pregnancy considerations, medication interactions, and stop rules.
| Grid item | What Dr. Campbell describes | Important interpretation boundary |
|---|---|---|
| Specimen | Blood serum testing for immune responses related to selected mycotoxins. | This is not nasal IgG, a nasal swab, a fungal culture, or a fungal PCR test. |
| Possible colonization sites | Dr. Campbell's materials discuss chronic mold and mycotoxin illness as a systemic problem and may raise concern for ongoing fungal burden or colonization beyond the original building exposure. | MyMycoLab serum IgG/IgE testing does not identify whether suspected colonization is in the nasal passages, sinuses, gut, lungs, skin, bloodstream, or elsewhere in the body. |
| IgG antibodies | Used in his model as evidence of immune recognition or body burden related to past or ongoing mycotoxin exposure. | IgG does not locate the exposure source and does not prove that fungus is colonizing the nasal passages, sinuses, gut, tissues, or home. |
| IgE antibodies | Used in his model as evidence of allergic-type immune reactivity to mycotoxin-related antigens. | IgE results must be interpreted with symptoms, allergy history, and clinician judgment; they are not a stand-alone mold illness diagnosis. |
| Repeat testing | His case materials describe repeating antibody testing during or after treatment to look for changes alongside symptom response. | Changing lab values do not automatically prove cure, relapse, colonization site, or need for prolonged antifungal therapy. |
| Clinical interpretation | Dr. Campbell places MyMycoLab results into a broader clinical story that may include water-damaged building exposure, persistent symptoms, immune findings, and treatment response. | This interpretation is not universally accepted as established medical consensus and should be discussed with a qualified clinician. |
His educational materials emphasize history of water-damaged buildings, symptoms that persist after exposure, and laboratory evidence he interprets as mycotoxin-related immune reactivity. In that framework, clinicians may consider possible ongoing fungal burden in the nasal passages, sinuses, gut, or elsewhere in the body, but LADA presents this as his clinical framework, not as proof that every chronically ill patient has mold illness.
In the MyMycoLab model, serum IgG and IgE antibody results are used to organize the suspected mycotoxin burden and immune response. These tests do not identify the physical location of fungal colonization and should not be confused with MARCoNS bacterial culture.
His cases and talks repeatedly pair treatment with leaving, remediating, or avoiding the suspected contaminated environment. This overlaps with broader mold/CIRS care: ongoing exposure can make interpretation of symptoms and labs difficult.
His public materials describe clinician-supervised oral itraconazole use for selected patients, sometimes for several months and in some examples six months or longer. LADA is not providing dose instructions, patient-selection criteria, or a recommendation to use itraconazole.
His approach describes tracking symptoms, repeat mycotoxin antibody results, and clinician monitoring during treatment. Any real-world monitoring plan should include conventional medication-safety checks such as liver enzymes, cardiac risk review, interaction review, and clear stop rules.
MyMycoLab antibody interpretation and prolonged antifungal treatment remain debated. Long-term itraconazole should never be started from a website protocol; it requires a qualified prescriber, medical history review, medication-interaction screening, and ongoing safety monitoring.
These prompts help patients ask better questions without trying to self-diagnose or self-treat.
Seek prompt medical assessment, urgent care, or emergency care if any of these are present.
Complicated bacterial sinusitis, orbital complications, meningitis, invasive fungal sinusitis, severe allergy, and other urgent conditions require conventional medical assessment. Do not delay urgent evaluation while waiting for specialty mold, MARCoNS, or mycotoxin testing.
MARCoNS testing is one piece of a larger clinical conversation. These pages help organize related questions.
Review exposure control, CIRS testing, Shoemaker/Nathan frameworks, binder sequencing, and clinician-supervised care boundaries.
Open Mold/CIRS PageUse LADA's care-pathway material to discuss histamine reactivity, medication sensitivity, dysautonomia, sleep, and pacing before aggressive treatment.
Open Care PathwaysFind research links, clinician directories, testing education, and appointment-preparation resources for complex chronic illness.
Open ResourcesUse the directory page to look for licensed clinicians familiar with Lyme, mold/CIRS, MCAS, environmental medicine, or complex chronic disease.
Open DirectoryMedical disclaimer: This information is provided for general education and does not constitute medical advice, diagnosis or treatment. MARCoNS, mycotoxin antibody testing and prolonged antifungal treatment remain areas of evolving research and clinical debate. Prescription antifungal treatment should only be undertaken under the supervision of a qualified healthcare professional.
These references are included for education and source transparency. They do not create a treatment recommendation.
