Currentblue cross blue shield - tennesseePolicy N/A

Diagnosis of Idiopathic Environmental Intolerance

Defines coverage stance for laboratory and diagnostic testing related to idiopathic environmental intolerance (IEI)/multiple chemical sensitivity for BlueCross BlueShield of Tennessee members.

Policy Summary

Payerblue cross blue shield - tennessee

PolicyDiagnosis of Idiopathic Environmental Intolerance

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateN/A

Next Review DateN/A

Key ActionOrder tests only when guideline-recommended clinical circumstances are documented; broad proprietary panels and tests to diagnose IEI are not covered.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

All listed laboratory testsDeclared as not meeting coverage criteria for IEI diagnosis

Breath H2/CH4 testsDoes not meet coverage for IEI (breath testing)

83918: 2Unit limit example

sens 54.5% / spec 83.2%Glucose breath test performance

sens 42% / spec 70.6%Lactulose breath test performance

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Coverage Criteria

Coverage criteria (not present in these chunks)

ALL of the following

In all circumstances, laboratory tests designed to confirm the diagnosis of idiopathic environmental intolerance (IEI) do NOT meet coverage criteria.
In all circumstances, screening of blood, saliva, serum, plasma, urine, and/or stool samples for volatile solvents, organic acids, and organophosphates does NOT meet coverage criteria.
In all circumstances, profiling of phthalates and parabens using blood, serum, plasma, saliva, urine, and/or stool samples does NOT meet coverage criteria.
For asymptomatic individuals, profiling of chlorinated pesticides (including DDE and DDT) using blood, serum, plasma, saliva, urine, and/or stool samples does NOT meet coverage criteria.
In asymptomatic individuals and/or during general encounters without abnormal findings, testing of blood, serum, plasma, saliva, urine, and/or stool samples for carnitine sufficiency, oxidative stress and antioxidant sufficiency, detoxification adequacy, methylation sufficiency, lipoic acid and CoQ10 sufficiency, and/or intestinal hyperpermeability does NOT meet coverage criteria.
In asymptomatic individuals and/or during general encounters without abnormal findings, testing of blood, serum, plasma, saliva, urine, and/or stool samples for vitamin sufficiency, mineral sufficiency, and/or nutritional analysis does NOT meet coverage criteria.
In asymptomatic individuals and/or during general encounters without abnormal findings, testing of blood, serum, urine, cerebrospinal fluid, fingernails, hair, and/or stool samples for metals does NOT meet coverage criteria.
Proprietary panels and a wide range of tests (including but not limited to micronutrient panels, detoxification, oxidative stress markers, and other specialty or laboratory-developed panels) are considered not medically necessary when ordered to evaluate or diagnose IEI, because IEI lacks reliable, testable characteristics and use of these tests for IEI is unsupported.
The use of breath hydrogen and/or breath methane tests to assess or diagnose the following conditions does NOT meet coverage criteria: (a) idiopathic environmental intolerance; (b) food allergies and sensitivities; (c) carbohydrate sensitivity or intolerance; (d) bacterial overgrowth, including but not limited to small intestinal bacterial overgrowth (SIBO); (e) digestive disorders; (f) constipation, diarrhea, or flatulence; (g) neurological/neuromuscular disorders; (h) rosacea; (i) obesity; (j) as part of a wellness visit and/or general encounter without abnormal findings.
Breath tests for trehalose, maltitol, sucrose, sorbitol, fructose, and other carbohydrates (and related substrates) are not supported by sufficient evidence for routine clinical use; blind sugar challenge remains the most valid technique to demonstrate clinical carbohydrate intolerance.
Lactulose breath testing has limited utility to discriminate IBS from healthy controls; variability in orocecal transit time contributes to false positives and limits test accuracy. While some guidelines endorse breath testing in selected symptomatic patients, breath testing should not be used for assessment of orocecal transit time, and testing protocols and interpretation remain variable across centers.
No FDA-approved or cleared tests for idiopathic environmental intolerance were identified. Many laboratories offer laboratory-developed tests (LDTs) for related analytes; LDTs are performed and validated in-house and are regulated under CLIA as high-complexity tests, but they are not FDA-approved or cleared.
Coverage of breath testing for SIBO and carbohydrate maldigestion should align with guideline-recommended clinical circumstances (for example, symptomatic patients with compatible clinical features and absence of alternative diagnoses); the North American consensus and ACG guidelines provide conditional recommendations for breath testing in certain symptomatic populations, but variability in evidence quality and testing methodology should be considered when ordering.

Coverage criteria aligned to guidelines

Covered when guideline-recommended clinical circumstances are documented:

ANY of the following

Breath testing (glucose hydrogen or lactulose hydrogen) for diagnosis of SIBO in symptomatic patients with compatible clinical features (eg, abdominal pain, gas, bloating, diarrhea) when alternative diagnoses have been excluded and testing will inform management; testing may include evaluation of methane in patients with constipation-predominant symptoms.
Breath testing for carbohydrate maldigestion (eg, lactose, fructose) in symptomatic patients when performed following guideline-recommended preparation, substrate selection, and duration (eg, at least 3 hours for fructose and lactose testing) and when bacterial overgrowth has been considered or ruled out as appropriate.
Breath testing used to assess antibiotic-responsive microbial colonization of the gastrointestinal tract when results will guide treatment decisions and are consistent with guideline recommendations and local practice standards.

No specific U.S. Food and Drug Administration (FDA) approval or clearance of a test for idiopathic environmental intolerance (IEI) was identified. Many laboratories have developed specific tests that they validate and perform in-house as laboratory-developed tests (LDTs). LDTs are regulated by CMS as high-complexity tests under CLIA '88. LDTs are not FDA-approved or cleared; however, FDA clearance or approval is not currently required for clinical use.

Proprietary panels and a wide range of tests (including but not limited to micronutrient panels, organic solvent/organic acid/organophosphate screens, phthalate/paraben profiling, metal testing, detoxification or methylation panels, oxidative stress assays, and related specialty panels) are considered not medically necessary for evaluation or diagnosis of IEI due to lack of evidence supporting their use in this condition.

Lactulose breath testing has limited utility for discriminating IBS from healthy controls and is subject to false positives related to variable orocecal transit time. Evidence on breath testing sensitivity and specificity is mixed; glucose breath testing shows higher specificity but variable sensitivity. Clinical symptoms are nonspecific for SIBO; breath testing may be useful in managing patients with compatible symptoms and absence of alternative diagnoses, but testing indications and interpretation should follow guideline recommendations.

The American College of Gastroenterology notes that nucleic acid testing for SIBO is under investigation and that large-scale studies are ongoing to evaluate its role; current evidence is insufficient to change standard practice.

Covered Indications

Targeted testing based on reported symptoms

Covered when ALL of the following are met:

Initial evaluation includes history, physical examination, and basic laboratory tests (complete blood count, serum electrolytes, glucose, urinalysis).

Further testing should be guided by reported symptoms and occupational/environmental history; questionnaires (eg EESI, PHQ-9) may be used as appropriate.

Symptom-directed further testing: Additional laboratory or diagnostic testing beyond basic labs is performed only if directly indicated by the patient’s reported symptoms or occupational/environmental exposure history.

Avoid broad panel testing in the absence of specific clinical indications.

Evaluation of suspected SIBO in symptomatic patients and assessment of methane in constipation

Covered when guideline-recommended clinical circumstances are documented for evaluation of suspected SIBO or methane-associated constipation.

Coding and Reimbursement

Reimbursement CPT Codes with unit limitsCPTCovered

83918	Organic acids; total, quantitative, each specimen
83919	Organic acids; qualitative, each specimen
83921	Organic acid, single, quantitative
82127	Amino acids; single, qualitative, each specimen
82136	Amino acids, 2 to 5 amino acids, quantitative, each specimen
82139	Amino acids, 6 or more amino acids, quantitative, each specimen
84585	Vanillylmandelic acid (VMA), urine
83150	Homovanillic acid (HVA)
83497	Hydroxyindolacetic acid, 5-(HIAA)
82656	Elastase, pancreatic (EL-1), fecal, qualitative or semi-quantitative

Procedure codes listed in documentmixed

82108	Aluminum.
82127	Amino acids; single, qualitative, each specimen.
82136	Amino acids, 2 to 5 amino acids, quantitative, each specimen.
82139	Amino acids, 6 or more amino acids, quantitative, each specimen.
82300	Cadmium.
82379	Carnitine (total and free), quantitative, each specimen.
82380	Carotene.
82441	Chlorinated hydrocarbons, screen.
82495	Chromium.
82507	Citrate.

1–10 of 42

1/5

Unit limits per date of service (selected codes)

83918Organic acids; total, quantitative — maximum 2 units per date of service

83919Organic acids; qualitative — maximum 1 unit per date of service

83921Organic acid, single, quantitative — maximum 2 units per date of service

82127Amino acids; single, qualitative — maximum 1 unit per date of service

(additional codes)See reimbursement section for other per-code unit limits where specified

SIBO culture threshold

Provider Actions and Billing Guidance

Billing Rule

Unit limits for listed CPT codes

For listed CPT codes, specific per-date-of-service unit limits apply and must be observed when billing.

83918 — Organic acids; total, quantitative, each specimen: maximum 2 units per date of service allowed.
83919 — Organic acids; qualitative, each specimen: maximum 1 unit per date of service allowed.
83921 — Organic acid, single, quantitative: maximum 2 units per date of service allowed.
82127 — Amino acids; single, qualitative, each specimen: maximum 1 unit per date of service allowed.

Prior Authorization

Breath testing prior authorization guidance

Breath testing (hydrogen and/or methane) may be clinically appropriate for diagnosing SIBO or carbohydrate maldigestion per expert guidance; however, coverage exclusions and local payer requirements apply. Prior authorization or submission of supporting documentation may be required to establish medical necessity.

Ordering Requirements

Note

Order tests only when symptom‑driven and initiated by the evaluating clinician

Ordering should be initiated by the evaluating clinician and be symptom‑driven; initial assessment must include history, physical exam, and basic laboratory testing before pursuing breath or specialized testing.

Evaluating clinician should document symptoms that justify testing and complete initial assessment (history, physical, CBC, electrolytes, glucose, urinalysis)

Documentation Required

Ensure symptoms compatible and document preparation and exclusion of alternative diagnoses

Order breath or specialized tests only when clinical symptoms are compatible, other diagnoses do not explain the presentation, and appropriate patient preparation and test protocols are followed and documented.

Ensure other diagnoses (eg, endoscopy or imaging) have been considered or excluded where applicable
Follow guideline recommendations for test duration and preparation (eg, lactose/fructose tests ≥3 hours)

Not Covered

Broad multi-analyte panels and tests intended to diagnose IEI are explicitly listed as not covered. This includes screening for volatile solvents, organic acids, organophosphates, phthalates, parabens, and profiling of chlorinated pesticides (e.g., DDE, DDT) in blood, serum, plasma, saliva, urine, or stool. The policy states these tests do not meet coverage criteria in any circumstance when ordered to confirm IEI.

The policy identifies breath tests for less-studied carbohydrates (such as trehalose, maltitol, sucrose, sorbitol) as not supported by adequate evidence and therefore not covered for routine clinical use. It also excludes nonvalidated immune-based tests and similar unproven assays marketed for diagnosing IEI/multiple chemical sensitivity (MCS).

No specific FDA-cleared or -approved tests for idiopathic environmental intolerance were identified in the review supporting this policy. The document notes that many assays described are laboratory-developed tests (LDTs) performed and validated in-house and regulated under CLIA; these LDTs are not FDA-approved.

Frequency Limits

Reimbursement codes with per-date-of-service unit notes

83918Organic acids; total, quantitative — maximum 2 units per date of service

83919Organic acids; qualitative — maximum 1 unit per date of service

83921Organic acid, single, quantitative — maximum 2 units per date of service

82127Amino acids; single, qualitative — maximum 1 unit per date of service

91065Breath hydrogen or methane test — listed in procedure codes (no per-date unit limit specified here)

Frequency limits

Frequency limits stated?

Definitions

Idiopathic environmental intolerance (IEI)

DefinitionIdiopathic environmental intolerance (IEI) is a subjective condition characterized by recurrent, nonspecific symptoms attributed to low levels of chemical, biologic, or physical agents without consistent objective diagnostic findings or laboratory tests.

Alternate nameFormerly called multiple chemical sensitivity (MCS)

Clinical featuresSymptoms are heterogeneous and lack reliable diagnostic laboratory markers; psychiatric comorbidity is common

EHS (Electromagnetic hypersensitivity)

DefinitionElectromagnetic hypersensitivity (EHS) is IEI attributed to electromagnetic fields with reported symptoms such as sleep disorders, migraines, and hypersensitivity.

OverlapMay overlap with conditions such as fibromyalgia and multiple chemical sensitivity

Background

Background: Idiopathic environmental intolerance (IEI), formerly termed multiple chemical sensitivity, is described as a subjective condition characterized by recurrent, nonspecific symptoms attributed to low-level environmental exposures without consistent objective diagnostic findings. Symptoms are heterogeneous and commonly overlap with psychiatric or functional disorders; the policy emphasizes that IEI lacks reliable laboratory markers and that many tests offered for IEI have not demonstrated clinical usefulness.

Revision History

2024-?policy_publication_or_updateLatest

Policy updated to state that a range of laboratory tests and panels do not meet coverage criteria for diagnosing idiopathic environmental intolerance (IEI), and to clarify that breath hydrogen/methane testing for IEI will be denied; guidance added on targeted clinical evaluation and documentation requirements.

Policy Summary

Payerblue cross blue shield - tennessee

PolicyDiagnosis of Idiopathic Environmental Intolerance

Policy CodePolicy N/A

Change TypeNo material changes

Effective DateN/A

Next Review DateN/A

Key ActionOrder tests only when guideline-recommended clinical circumstances are documented; broad proprietary panels and tests to diagnose IEI are not covered.

SourceLink

On This Page

Symptomatic patients appropriate for testing: Breath testing (glucose or lactulose hydrogen/methane) is suggested in symptomatic patients (eg bloating, gas, abdominal pain, diarrhea) when clinical evaluation excludes other diagnoses and conditions that predispose to SIBO are considered.

North American Consensus and ACG provide conditional/moderate-quality recommendations for breath testing in these patients.

Evaluate methane in constipation: Assess for excessive methane excretion on breath testing in symptomatic patients with constipation or suspected slow gastrointestinal transit.

North American Consensus suggests evaluation for methane when associated with clinical constipation.

Test selection: Select glucose or lactulose substrate based on clinical context; glucose may have higher specificity while lactulose may have different predictive response to therapy.

Consider test limitations including variability in orocecal transit time and potential false positives (Rangan et al.).

Diagnosis of lactose or fructose malabsorption when clinically suspected

Covered when diagnostic test performance standards and pre-test considerations are met.

Test duration for lactose/fructose: Lactose and fructose breath tests should be performed for at least 3 hours when used to evaluate suspected malabsorption.>= 3 hours

Per North American Consensus guidance and literature review (Rezaie et al.; Usai-Satta et al.).

Exclude bacterial overgrowth prior to testing: Bacterial overgrowth should be considered and ruled out before performing lactose or fructose breath testing to avoid confounding results.

North American Consensus recommends excluding SIBO before carbohydrate maldigestion testing.

Detection of lactase deficiency, fructose intolerance, bacterial overgrowth, or oro-cecal transit using breath H2/CH4 testing

Covered when testing is ordered for recognized gastrointestinal indications and documented appropriately.

Indications for H2/CH4 breath testing: Breath hydrogen and/or methane testing may be used to detect lactase deficiency, fructose intolerance, small intestinal bacterial overgrowth, or to assess oro-cecal gastrointestinal transit when ordered for these specific indications.

Procedure code example: 91065 (breath hydrogen or methane test). Guidelines recommend breath testing for SIBO and carbohydrate maldigestion in appropriate clinical contexts.

Documentation requirements: Documentation must support compatible symptoms and the absence of alternative diagnoses (eg endoscopy or imaging) when breath testing is ordered for these indications.

Lack of standardization in test performance underscores need for clear symptom-driven documentation (Usai-Satta et al.; Rangan et al.).

SIBO culture threshold

Evidence qualityRecommendation based on Low quality evidence per North American Expert Consensus

ContextThreshold applies when small bowel culture is considered for SIBO diagnosis

None listed

StatusNo specific threshold or limit listed in this section

NoteRefer to applicable reimbursement code table for per-code unit limits where provided

ActionNo additional thresholds recorded in document

Breath testing suggested for SIBO and carbohydrate maldigestion when clinically appropriate.
Document clinical symptoms, prior evaluations (including endoscopy/imaging when applicable), and rationale for testing.
Be aware payer may require prior authorization or additional documentation to support medical necessity.

Billing Rule

Procedure codes — reference

Use the listed procedure codes for provider billing reference. These codes are provided as a general reference and may not be all-inclusive.

91065 — Breath hydrogen or methane test.
S3708 — Gastrointestinal fat absorption study.
89125 — Fat stain, feces, urine, or respiratory secretions.

Denial Risk

Denial for IEI diagnostic testing

Ordering laboratory tests intended to confirm a diagnosis of idiopathic environmental intolerance (IEI) is excluded from coverage and will be denied. Similarly, the use of breath hydrogen and/or methane testing to assess or diagnose IEI is not covered.

Laboratory tests designed to confirm IEI — NOT COVERED; will be denied.
Breath hydrogen and/or methane testing to assess/diagnose IEI — NOT COVERED; will be denied.

Documentation Required

High variability/false positives due to orocecal transit time

Breath testing has recognized limitations that can increase false-positive results; the largest documented contributor is variability in orocecal transit time leading to premature substrate fermentation by colonic flora rather than small-bowel organisms.

High variability in orocecal transit time can cause false-positive lactulose breath tests due to colonic fermentation.
Sensitivity and specificity vary by substrate (e.g., lactulose vs glucose); interpret results in clinical context.

Documentation Required

Lack of standardization in indications, preparation, performance, and interpretation

There is a lack of standardization across centers for indications, preparation, performance, and interpretation of breath testing. Ensure documentation includes the clinical indication, patient preparation and protocol used, substrates and timing, and the method of interpretation.

Document clear clinical indication and prior evaluations that justify testing.
Record patient preparation (e.g., diet, antibiotics/probiotics held), substrate used (lactulose, glucose, lactose, fructose), sampling duration (e.g., ≥3 hours for lactose/fructose per guidelines), and interpretation criteria.
Because of heterogeneity, include center-specific protocol details when submitting for authorization or claims review.

Documentation Required

LDT/CLIA documentation

Many specialized tests cited in this policy are laboratory-developed tests (LDTs) performed and validated in-house and are regulated under CLIA as high-complexity tests. LDTs are not FDA-cleared/approved; include CLIA-certification and validation documentation when requested.

If submitting claims for LDTs, be prepared to provide documentation of CLIA certification and laboratory validation methods upon request.
LDTs should be billed with appropriate codes, and supporting lab validation/description may be required for medical review.

No explicit frequency limits stated in this section

ImplicationOrdering frequency should follow clinical guidelines and local practice; document recommends standardized preparation and duration for specific tests

ActionRefer to clinical guidance (e.g., North American Consensus) for test duration and repeat testing considerations

NatureSubjective symptom attribution without consistent objective findings

Lactulose breath test (LBT)

Test nameLactulose breath test (LBT)

DescriptionTwo- or three-hour breath testing after lactulose ingestion measuring hydrogen and methane; early peaks may reflect small bowel bacterial metabolism but can be confounded by rapid substrate delivery to the colon.

LimitationsVariable oral–cecal transit time and lack of standardization across centers can produce false positives/negatives

Glucose breath test (GHT)

Test nameGlucose breath test (GHT / GHBT)

PerformanceReported higher specificity and sensitivity than lactulose in some reviews (example: sensitivity 54.5% and specificity 83.2% vs lactulose 42.0%/70.6%).

Recommended useSuggested by guidelines for SIBO diagnosis and may be preferred when higher specificity is desired

Laboratory-developed test (LDT)

DefinitionLaboratory-developed test (LDT): a test developed, validated, and performed in-house by a laboratory; regulated under CLIA as high-complexity tests and not FDA-approved/cleared.

RegulationLDTs are regulated by CMS under CLIA '88; FDA clearance/approval is not required for clinical use per document

ImplicationDocumentation should support CLIA high-complexity laboratory performance and validation where applicable

Breath hydrogen/methane test (91065)

DefinitionBreath hydrogen/methane test (91065): measures exhaled hydrogen and methane used for detection of lactase deficiency, fructose intolerance, small intestinal bacterial overgrowth (SIBO), or oro-cecal gastrointestinal transit.

Common usesDetection of lactase deficiency, fructose intolerance, bacterial overgrowth, and assessment of oro-cecal transit time (though guidelines advise against using BT for transit time assessment).

LimitationsSensitivity/specificity vary by substrate and methodology; results can be confounded by transit time and substrate delivery