Medical Necessity - Allergy Testing (general)
Aetna considers specific allergy testing medically necessary for members with clinically significant allergic history of symptoms when ALL of the following criteria are met:
Symptoms are not adequately controlled by empiric conservative therapy; and
Testing must correlate specifically to the member's history, risk of exposure and physical findings; and
Test technique and/or allergens tested must have proven efficacy demonstrated through scientifically valid medical studies published in the peer-reviewed literature.
Epicutaneous (scratch, prick or puncture) testing
Epicutaneous (scratch, prick or puncture) testing is considered medically necessary when IgE-mediated reactions are suspected and testing matches the clinical history. Perform percutaneous testing for:
Hymenoptera (stinging insects)
Specific drugs (e.g., penicillins and macromolecular agents)
Intradermal (Intracutaneous) testing
Intradermal (intracutaneous) testing is considered medically necessary when IgE-mediated reactions are suspected for selected allergens and when percutaneous tests are negative or insufficient. Do not use intradermal testing for food allergy.
Hymenoptera venom allergy (stinging insects)
Specific drugs (e.g., penicillins and macromolecular agents)
Number limits - Epicutaneous and Intracutaneous
Typical number limits for skin testing (may vary by clinical need):
Evaluation of inhalant allergy may require up to 70 percutaneous (epicutaneous) tests.
Follow-up intracutaneous testing may include up to 40 intradermal tests (often performed when percutaneous tests are negative).
When determining starting dose for immunotherapy in highly allergic patients, up to 14 skin endpoint titration (SET) dilutional tests may be necessary; an additional 40 antigens or up to 80 IDT injections may be medically necessary if initial results are positive.
Skin Endpoint Titration (SET / IDT)
Skin Endpoint Titration (SET / IDT) — also called intradermal dilutional testing — is used to determine the starting dose for immunotherapy in highly allergic individuals.
Members highly allergic to hymenoptera venom (stinging insects).
Members highly allergic to inhalants.
When used to determine starting dose for immunotherapy, up to 14 titration tests may be necessary; if any initial titration test is positive, an additional 40 antigens or up to 80 IDT injections may be medically necessary.
SET is inappropriate as a substitute for standard skin testing; use only when needed to establish a safe starting concentration for immunotherapy.
Skin Patch Testing
Patch testing is considered medically necessary for diagnosing allergic contact dermatitis.
Skin patch testing for contact dermatitis (up to 80 units is considered medically necessary).
Photo Patch Testing and Photo Tests
Photo-patch testing and photo tests are used to evaluate photo-allergy and photosensitivity disorders.
Photo-patch testing for diagnosing photo-allergic contact dermatitis.
Phototests for evaluating photosensitivity disorders.
Bronchial Challenge Test
Bronchial challenge testing (e.g., methacholine, histamine, or antigen) is used to define asthma or airway hyperreactivity when indicated.
When bronchial challenge testing is being used to identify new allergens for which skin or blood testing has not been validated.
When skin testing is unreliable or cannot be performed.
Exercise Challenge Testing
Exercise challenge testing is medically necessary for diagnosis of exercise-induced bronchospasm.
Evaluation of exercise-induced bronchospasm (exercise challenge testing).
Ingestion (Oral) Challenge Test
Ingestion (oral) challenge testing is considered medically necessary for evaluation of suspected food or other non-drug reactions and for certain drug challenges when strict conditions are met.
Food or other substances (e.g., metabisulfite).
Drugs when ALL of the following are met:
History of allergy to the particular drug; and
There is no effective alternative drug; and
Treatment with that drug class is essential.
In Vitro IgE Antibody Tests
In vitro IgE antibody tests (e.g., RAST, MAST, FAST, ELISA, ImmunoCAP) are medically necessary in specific clinical scenarios and may be used as an initial screen in lieu of skin testing within limits.
Indications for in vitro testing: patients on skin-test–suppressive medications that cannot be discontinued; widespread skin disease (dermatographism, generalized eczema); uncooperative patients (small children, impaired individuals); history suggesting high anaphylaxis risk with skin testing; evaluating cross-reactivity between insect venoms; adjunctive testing for ABPA or certain parasitic diseases.
Initial allergy screen limits: up to 40 inhalant tests and up to 12 food/other tests. Additional tests may be medically necessary if any initial test is positive; if all initial tests are negative, further in vitro testing beyond the initial screen is not considered medically necessary.
Operational notes: use in vitro testing when skin testing is contraindicated or impractical (medication suppression, skin disease, patient inability). Ensure testing correlates with clinical history and document reasons why skin testing could not be performed.
Total Serum IgE
Total serum IgE measurement (e.g., PRIST, RIST) is used in specific diagnostic evaluations.
Diagnostic evaluation for known or suspected allergic bronchopulmonary aspergillosis (ABPA).
Evaluation for hyper IgE syndrome.
Lymphocyte Transformation Tests
Lymphocyte transformation tests have limited allergy indications but are useful for specific non-allergy diagnoses.
Medically necessary: evaluation of persons with sensitivity to beryllium.
Medically necessary: evaluation of congenital or acquired immunodeficiency diseases affecting cell-mediated immunity (examples: severe combined immunodeficiency, common variable immunodeficiency, X-linked hyper IgM, Nijmegen breakage syndrome, reticular dysgenesis, DiGeorge syndrome, Nezelof syndrome, Wiscott-Aldrich syndrome, ataxia telangiectasia, chronic mucocutaneous candidiasis).
Medically necessary: evaluation in thymoma or to predict allograft compatibility in transplant setting.
Experimental/investigational: lymphocyte transformation tests are considered experimental and investigational for evaluation of persons with allergies or other hypersensitivities (including metal allergy testing).
Alpha-Gal (Meat) Allergy Testing
Alpha-gal (galactose-alpha-1,3-galactose) IgE testing is medically necessary when clinical presentation after mammalian meat ingestion meets specified criteria.
Testing is medically necessary when EITHER of the following occur within 3–6 hours after ingestion of mammalian meat:
Urticaria, angioedema, or anaphylaxis.
Gastrointestinal symptoms (abdominal pain, diarrhea, vomiting) accompanied by presyncope or syncope.
Ara h 2 Testing for Peanut Allergy
Ara h 2 specific IgE testing is considered medically necessary when peanut allergy is suspected and can aid diagnostic evaluation.
Ara h 2 testing for persons with suspected peanut allergy.
Allergy Re-testing and Repeat Percutaneous Testing
Routine allergy re-testing and repeat percutaneous testing are limited.
Repeat percutaneous testing is allowed if new sensitivities emerge during or after allergen immunotherapy, or if the person has failed to respond to allergen immunotherapy.
Routine repeated percutaneous allergy testing for monitoring response to immunotherapy is considered not medically necessary.
Performance of Both Percutaneous and IgE RAST for Same Allergens
Performing both percutaneous (skin prick) testing and IgE serologic testing for the same allergens is generally not necessary.
Performance of both percutaneous allergy tests and IgE RAST tests (blood) for the same allergens is considered not medically necessary.
Allergy Immunotherapy (General)
Allergy immunotherapy (subcutaneous) is considered medically necessary for selected IgE-mediated conditions when specific criteria are met.
Covered indications include allergic (extrinsic) asthma, dust mite atopic dermatitis, Hymenoptera venom sensitivity, mold-induced allergic rhinitis, perennial rhinitis, seasonal allergic rhinitis or conjunctivitis.
Required conditions: member has severe seasonal or perennial IgE-dependent symptoms after natural exposure AND BOTH of the following are met: member has skin test and/or serologic evidence of IgE-mediated sensitivity to a potent extract of the allergen; and avoidance or pharmacologic therapy cannot control symptoms or causes unacceptable side effects. OR
Life-threatening IgE-mediated allergy to insect stings (bees, hornets, wasps, fire ants). OR
Hypersensitivity to allergens that cannot be managed by medication or avoidance.
Allergy immunotherapy is considered experimental and investigational for all other indications.
Rapid Desensitization (rush, cluster, acute)
Rapid desensitization (rush, cluster, acute) may be medically necessary in specific situations; preparations and premedication considerations apply.
Indications (ANY): allergy to a particular drug that cannot be treated effectively with alternative medications; insect sting hypersensitivity (hymenoptera); members with moderate to severe allergic rhinitis who need treatment during or immediately before the season.
Operational notes: allergens should be individually prepared for the patient and based on appropriate skin or in vitro testing. Rapid desensitization is considered experimental and investigational for other indications. If pregnancy is contemplated and initiation of immunotherapy is required, rapid desensitization is an acceptable approach.
Premedication and procedural notes: premedication regimens (antihistamines, corticosteroids) may be used per protocol to reduce reaction risk; specific premedication for RDD to paclitaxel and other agents should follow published clinical guidance and be documented in the medical record.
Epinephrine Kits
Epinephrine auto-injector kits are indicated to prevent or treat anaphylactic reactions in high-risk individuals.
Persons with a history of life-threatening reactions to insect stings, foods, drugs, or other allergens.
Individuals with severe asthma at risk for anaphylaxis.
Individuals who require epinephrine during immunotherapy.
Epinephrine kits are considered experimental and investigational for indications other than those listed above.
Experimental and Investigational - Tests and Procedures
Aetna considers many tests and procedures experimental and investigational for allergy evaluation when there is insufficient evidence of effectiveness.
Examples of tests/procedures considered experimental/investigational include (but are not limited to): ALCAT test, IgG4 and other unproven antibody or leukocyte activation assays for routine allergy diagnosis, commercial/novel unvalidated products (e.g., Allergenex, Alzair Allergy Blocker, MBG AlerjSTOP), autologous whole-blood or serum acupoint injection for chronic urticaria, ligelizumab for chronic spontaneous urticaria (investigational unless otherwise approved), skin patch testing for irritable bowel syndrome, intradermal testing to foods (not appropriate due to high false-positive rate and risk of anaphylaxis), intradermal grass pollen immunotherapy and other intradermal immunotherapy approaches that lack evidence, subcutaneous depot steroids or intramuscular depot steroids for allergic rhinitis, chemical cautery (silver nitrate) of nasal mucosa for allergic rhinitis, oral immunotherapy (OIT) for peanut allergy outside established protocols or clinical programs.
Operational note: Documentation in the medical record must support clinical indications, prior therapies tried, rationale for experimental/novel testing if used (including review of evidence and informed consent), and any prior authorization when required.
Clinical statements / guidance and Documentation requirements
Additional clinical and operational guidance and documentation requirements to support medical necessity and proper billing.
Documentation requirements: clearly document history of allergic symptoms, exposures, prior conservative therapy and response, physical findings, indication for specific test, and why alternative testing (or discontinuation of suppressive medications) is not feasible when applicable.
Clinical guidance summary: diagnostic cut-offs and interpretation should follow validated, peer-reviewed sources; use component-resolved diagnostics (e.g., Ara h 2) where evidence supports improved specificity for clinical decision-making.
Special populations/conditions: for food protein-induced enterocolitis syndrome (FPIES), diagnosis is primarily clinical and oral food challenge under controlled conditions may be required; skin testing and specific IgE testing are of limited value for typical FPIES.
Percutaneous testing after immunotherapy: repeat percutaneous testing is permitted for new sensitivities or lack of response to immunotherapy; routine percutaneous testing solely for monitoring immunotherapy response is not medically necessary.