Medical Policy: 02.01.02
Original Effective Date: November 2003
Reviewed: February 2021
Revised: February 2021
This policy contains information which is clinical in nature. The policy is not medical advice. The information in this policy is used by Wellmark to make determinations whether medical treatment is covered under the terms of a Wellmark member's health benefit plan. Physicians and other health care providers are responsible for medical advice and treatment. If you have specific health care needs, you should consult an appropriate health care professional. If you would like to request an accessible version of this document, please contact customer service at 800-524-9242.
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
Allergic or hypersensitivity disorders can manifest themselves as generalized systemic reactions as well as localized reactions in any organ system of the body. Numerous agents, e.g., pollen, mold, dust mites, animal dander, insect stings, foods or drugs may precipitate allergic or hypersensitive reactions. For details on treatment of allergies, see Policy 02.01.01, Allergy Immunotherapy.
Allergy is a hypersensitive reaction that is usually manifested in the clinical form of allergic asthma, hay fever or eczema developing within minutes to a few hours after exposure to an antigen. The most common types of allergies are rhinitis, asthma, food allergy, insect sting allergy, drug allergy and contact dermatitis. Allergy testing is focused on determining what allergens cause a particular reaction and the degree of the reaction and provides justification for recommendations of specific avoidance measures in the home or work environment or the institution of particular medicines or immunotherapy. There are virtually no age limitations for performance of skin tests. However, skin test reactivity may be diminished in infants and the elderly. Types of allergy testing include in vivo, in vitro, provocation testing, and controversial allergy tests. The umbrella term ‘food hypersensitivity or food sensitivities’ can be used to describe any ‘adverse reaction to food’. The term ‘food allergy’ refers to the subgroup of food-triggered reactions in which immunologic mechanisms have been implicated, whether IgE- mediated, non-IgE-mediated, or involving a combination of IgE- and non-IgE-mediated etiologies. All other reactions to food that were in the past sometimes referred to as ‘food intolerance’ or ‘food sensitivities’ constitute non-allergic food hypersensitivity reactions and are not considered allergies.
Allergy tests detect the presence of IgE antibodies to a particular allergen, or something that causes an allergic reaction. A positive test suggests allergic sensitization to a specific allergen. There are several in-vitro tests available to diagnose allergies, however, the National Medical and Research Center believes that standard intradermal or epicutaneous skin tests in correlation with a thorough medical history and physical examination best serves the patient. A positive skin test alone does not diagnose an allergy; it must correlate with symptoms experienced when the patient has an allergen exposure.
Ideally, the clinical history should provide enough information to form an opinion about whether a patient’s symptoms are due to allergies and if so, what they are likely to be allergic to. The purpose of a diagnostic test is to determine whether a patient’s symptoms are caused by an allergic disease as opposed to other common causes. Diagnostic testing also can better define the specific triggers when the history alone is unclear. Neither allergy blood testing nor skin testing should be used for screening: they are most useful as confirmatory tests when the patient’s history is compatible with an IgE-mediated reaction.
The management of an allergic patient should include a comprehensive history, physical examination and should include confirming the cause of allergies. Once the agent is identified, treatment is provided by avoidance, medication or immunotherapy. The physician supervised oral food challenge remains the gold standard for food allergy diagnosis. Skin testing would be the first line of testing for the majority of patients. In vitro testing would be appropriate for those with the inability to stop specific medications and those that have had severe allergic responses to medicine, food, inhalants, and insects. It would be inappropriate to use in vitro testing as the first line of testing unless specific indications are present.
The advantage of skin tests is that they are rapid, sensitive and specific, safe and relatively inexpensive per test. The disadvantages of skin tests are that there is a small risk of a systemic reaction. The sensitivity of blood allergy testing is approximately 25% to 30% lower than that of skin testing, based on comparative studies.
The skin of infants may be less reactive, yielding more false-negative results, although this difference has not been formally studied. Nevertheless, positive results are commonly obtained in infants with a history consistent with food allergy. Thus, skin testing can be performed even in infants and young children (greater than 6 months of age) when indicated and with appropriate precautions.
The blood tests for allergic disease are immunoassays that measure the level of IgE specific to a particular allergen. Levels of specific IgE have been shown to depend on age, allergen specificity, total serum IgE, and, with inhalant allergens, the season of the year. Evidence of sensitization to a particular allergen (ie, a positive blood test result) is not synonymous with clinically relevant disease (ie, clinical sensitivity). In Vitro Specific IgE levels higher than 0.35 KU/L suggests sensitization but do not correlate with clinical disease in all situations. Different commercial specific IgE assays are also not always equivalent. In vitro allergy blood tests can give false positive results due to nonspecific binding of antibody in the assay. Prospective studies exist to identify IgE levels that may predict clinical reactivity with greater than 95% certainty. This level of understanding does not exist for all foods, drugs, latex or allergens. Allergen testing in serum is designed to detect the presence of allergen-specific IgE. A positive test for allergen-specific IgE confirms the presence of the antibody only. Actual reactivity must be determined by history or supervised challenge.
IgG antibodies to allergens such as foods can be detected and quantified by Unicap or ELISA techniques. The presence of IgG antibodies, however, does not indicate allergy to these environmental substances. Detection of IgG antibodies, IgG subclasses, or IgG/IgG4 antibody ratios were discredited as reliable diagnostic tools.
Food-specific IgG4 does not indicate (imminent) food allergy or intolerance, but rather a physiological response of the immune system after exposition to food components. Therefore, testing of IgG4 to foods is considered as irrelevant for the laboratory work-up of food allergy or intolerance and should not be performed in case of food-related complaints.
Patch testing can be performed either using a preloaded thin-layer rapid use epicutaneous testing kit of 36 chambers or with a panel of antigens loaded individually in a chamber system recommended by the North American Contact Dermatitis Group (NACDG) Research Group or the American Contact Dermatitis Society (ACDS). The patch test procedure can induce an eczematous reaction in miniature by applying suspect allergens to normal skin, allowing the physician to determine a specific patient allergy. Patch tests are applied to the skin on the patient's back and left in place for 48 hours. The test is interpreted after 48 hours, and typically once again at 72 hours or 96 hours, and the reactions are systemically scored and recorded. The patient is then informed and educated regarding specific allergies and avoidance of exposure. Avoidance of the identified allergen(s) is critical to patient improvement and resolution of the dermatitis.
Some chemicals produce an allergic reaction only when exposed to light (usually ultraviolet type A light, UVA). Patients who are oversensitive to light and those with a rash that appears on parts of the body normally exposed to light (mostly the face, the 'V' of the neck and the hands) but that does not appear in areas shielded from the light (eg under the chin and the triangle between the nose and the mouth) should have a photo or phot-patch test to determine if light is causing the allergic reaction. Photo testing and photo patch testing are indicated to evaluate a nonspecific photo sensitive dermatitis, photo sensitive allergic contact dermatitis or photo sensitive pruritus, to determine the causative antigen. Photo-patch testing should be done in clinical settings with the expertise, materials, and equipment to perform the procedure. In brief, duplicate applications of the suspected photo-sensitizer(s) are placed on either side of the upper back, and occluded for 24 to 48 hours. A recent study suggests that 2 days of occlusion before irradiation of allergens is more sensitive at detecting photoallergy. After patch removal, one side of the back is then irradiated with 5 J cm 2 of UVA and the other side is left open but untreated as the control. Both irradiated and unirradiated sides are then measured 48 hours after irradiation for a response. Photo tests are used to evaluate skin abnormalities—such as rash, itching, blisters, and hives—that are either caused or exacerbated by exposure to sunlight. In standard photo tests, small areas of skin are irradiated with different doses of long- and short-wave ultraviolet (UVA and UVB) and visible light, and then observed for a reaction.
The American Academy of Allergy Asthma and Immunology (AAAAI) Expert Panel suggests that the atopy patch test should not be used in the routine evaluation of noncontact food allergy. Insufficient evidence exists to support the use of the atopy patch test for the evaluation of food allergy. Although a number of studies have reported that the patch testing may be useful in the evaluation of food allergies in patients with atopic dermatitis and eosinophilic esophagitis, there is no agreement on the appropriate reagents, methods, or interpretation of these tests. When compared with oral food challenges, patch testing shows highly variable sensitivity and specificity among different studies.
Basophil activation test simulates an oral challenge, in a test tube. The patient’s blood is drawn, exposed to the allergen and the basophils – immune cells involved in a reaction – are analyzed using flow cytometry.
This food allergy test involves a proprietary epitope mapping platform that looks at how a patient’s IgE antibodies bind to individual parts of the protein’s components, called epitopes.
The Choosing Wisely initiative includes the following recommendations from the American Academy of Asthma, Allergy, and Immunology regarding allergy testing:
One of the AAAAI’s (American Academy of Allergy, Asthma and Immunology) “Five Things Physicians and Patients Should Question” (2012) noted that “Appropriate diagnosis and treatment of allergies requires specific IgE testing (either skin or blood tests) based on the patient’s clinical history. The use of other tests or methods to diagnose allergies is unproven and can lead to inappropriate diagnosis and treatment”. The AAAAI stated that “Don’t perform unproven diagnostic tests, such as immunoglobulin G (IgG) testing or an indiscriminate battery of immunoglobulin E (IgE) tests, in the evaluation of allergy”.
Measurement of allergen-specific IgG or IgG4 antibodies in the evaluation of food allergy is considered a test of unproven or no value by the American Academy of Allergy, Asthma & Immunology - AAAI, American College of Allergy, Asthma & Immunology - ACAAI, the Joint Council of Allergy, Asthma and Immunology - JCAAI, and the American Gastroenterological Association - AGA.
Updated Practice Parameter (2012) states: Summary Statement 127. IgG and IgG subclass antibody tests for food allergy do not have clinical relevance, are not validated, lack sufficient quality control, and should not be performed.
Evidence of IgE sensitization to common food and appropriate aeroallergens can support a diagnosis of food allergy in conjunction with clinical history and/or food challenge. The clinical utility of measuring serum food IgE and to generate a successful elimination diet needs further investigation. There are no unconventional tests which can be recommended as an alternative or complementary diagnostic tool in the workup of suspected food allergy, and their use should be discouraged.
The general recommendations include:
For details on treatment of allergies, see Policy 02.01.01, Allergy Immunotherapy.
The following allergy tests are considered medically necessary, if the following indications are met, with the following limits:
Percutaneous (scratch, puncture, prick) and intracutaneous (intradermal) allergy testing are considered medically necessary and, therefore, covered for the diagnosis, evaluation, and treatment of allergies when there are signs and symptoms or a diagnosis suggestive of an allergy. Skin testing may be used for the evaluation of allergen-specific IgE to inhalants, foods, drugs and venom in the following conditions: respiratory/inhalant allergy, food allergy, venom allergy, drug allergy. Intradermal testing has no place in aeroallergen and food allergen testing. It is most commonly used in testing for drug and venom allergy.
Percutaeous testing has the following limitations:
A total of 70 scratch, puncture, or prick allergy tests are eligible for reimbursement per calendar year (CPT code 95004).
A total of 40 intracutaneous allergy tests (which should only follow negative scratch, puncture, or prick tests) are eligible for reimbursement per calendar year (CPT codes 95024 and 95028).
Skin serial endpoint titration (SET) for determination of a safe starting dose for testing (e.g., pre-operative testing, safe starting dose for therapy/antibiotics/biologics) or immunotherapy when there is potential for the specific allergen in question to produce a severe systemic reaction or anaphylaxis and it is an approved indication for immunotherapy. Serial endpoint titration (SET) testing (eg, intradermal dilutional testing [IDT]) is considered medically necessary with a total of 80 tests being eligible for reimbursement for CPT code 95027, 27 tests being eligible for reimbursement for CPT code 95017, or 19 tests eligible for reimbursement for CPT code 95018.
Patch testing is the gold standard method of identifying the cause of allergic contact dermatitis. This testing is indicated to evaluate:
to determine the causative antigen. It is a diagnostic test reserved for patients with skin eruptions for which a contact allergy source is likely.
Patch testing (95044) is limited to 42 units.
Standard panels of allergens for patch testing are available from various commercial sources. Each standard patch test unit includes 35 common allergens and a negative control. In addition to the standard series of 36 patch tests, six (6) additional allergens may be performed initially. Allergy testing in excess of the above limits is considered not medically necessary.
Patch test should not be used in the routine evaluation of noncontact food allergy. Insufficient evidence exists to support the use of the atopy patch test for the evaluation of food allergy. Patch testing for food allergy will be considered not medically necessary.
Patch testing outside of these diagnoses will be considered not medically necessary.
Photo testing (95056) and photo patch testing (95052) are indicated to evaluate:
Photo testing is limitied to 20 units. Photo testing and photo-patch testing outside of these diagnosis or quantity limits will be considered not medically necessary.
Multiallergen screening (CPT code 86005) is a qualitative test that does not quantify specific antigens; therefore, it is considered not medically necessary and not covered. Multiallergen screening is considered not medically necessary and, therefore, not covered because the available published peer-reviewed literature does not support its use in the treatment of illness.
The following allergy tests are considered investigational because the scientific literature has not provided proof of their efficacy:
The use of in vitro (blood) (86003) allergy testing for IgE should be limited to individuals where skin testing is not possible. There would rarely be a need for testing beyond 36 tests per year. Testing implemented beyond 36 tests will be denied as not medically necessary.
Specific IgE in vitro tests (86003 or 86008) for inhalant allergens (pollens, molds, dust, mites, animal danders) anaphylactic shock due to foods or insect sting, or for evaluation of cross-reactivity between insect venoms may be considered medically necessary when the following criteria are met:
*Specific IgE in vitro testing is considered medically necessary only after physician determination that one of the aforementioned conditions precludes the use of direct skin testing. Specific IgE in vitro tests should be used judiciously and include testing only for those allergens that could be reasonably suspected regardless of test kit packaging. Diagnostic screening is limited to 36 allergen specific antibodies but must be personalized to the individual.
Testing for other immunoglobulin (e.g. IgG, IgG4, IgA, IgM, IgD) or subclasses to determine allergies is considered investigational.
Precision diagnostics for food allergy with non-personalized large panel testing is considered investigational.
Allergy testing is generally considered diagnostic: retesting is considered not medically necessary on an annual or more frequent basis.
To report provider services, use appropriate CPT* codes, Modifiers, Alpha Numeric (HCPCS level 2) codes, Revenue codes, and/or diagnosis codes.
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