**Overview:**  
Allergy testing is performed to determine a patient's immunologic sensitivity
or reaction to particular allergens for the purpose of identifying the cause
of the allergic state.  It is based on findings during a complete medical and
immunologic history, and appropriate physical exam obtained by face-to-face
contact with the patient.

**Indications:**  
Allergy skin testing is a clinical procedure that is used to evaluate an
immunologic response to allergenic material.  It would not be expected that
all patients would receive the same tests or the same number of sensitivity
tests. The number and type of antigens used for testing must be chosen
judiciously given the patient's presentation, history, physical findings, and
clinical judgment.

To be covered by Medicare, the antigens must meet all of the following
criteria:

1. Skin testing must be performed based on a complete history and physical exam,  
2. Proven efficacy as demonstrated through scientifically valid peer reviewed published medical studies, and  
3. Exist in the patient's environment with a reasonable probability of exposure

Allergy testing can be broadly subdivided into two methodologies:

**A. In vivo testing** (skin tests): this testing correlates the performance
and evaluation of selective cutaneous and mucous membrane tests with the
patient's history, physician examination, and other observations.

**1.  Percutaneous Testing** (scratch, puncture, prick) and is used to
evaluate immunoglobulin E (IgE) mediated hypersensitivity.  Percutaneous tests
require medical supervision, since there is a small but significant risk of
anaphylaxis. Overall, skin testing is quick, safe, and cost-effective.  It
remains the test of choice in most clinical situations where immediate
hypersensitivity reactions are suspected.

Percutaneous testing is the usual preferred method for allergy testing.
Medicare covers percutaneous (scratch, prick or puncture) testing when IgE-
mediated reactions occur with **any** of the following:

a. Inhalants.  
b. Foods. (Patients present with signs and symptoms such as urticarial,
angioedema, esosinophilic esophagitis, or anaphylaxis after ingestion of
specific foods. Testing for food allergies in patients who present with
wheezing is occasionally required.)  
c. Hymenoptera (stinging insects).  
d. Specific drugs (penicillins, macromolecular agents, enzymes, and egg-
containing vaccines).  Skin testing is unreliable with other drugs.

**2.  Intracutaneous/Intradermal Tests** are usually performed when increased
sensitivity is the main goal such as when percutaneous tests are negative and
there is a strong suspicion of allergen sensitivity.  Intradermal tests are
injections of small amounts of antigen into the superficial layers of the
skin. The usual testing program may include 2 concentrations of an extract: a
weaker concentration and a stronger concentration. It would not be expected
that 3 or more concentrations of one extract would be medically necessary.
Medicare covers intradermal (intracutaneous) testing when IgE-mediated
reactions occur to **any** of the following:

a. Inhalants.  
b. Hymenoptera (stinging insects).  
c. Specific drugs (penicillin's and macromolecular agents).  
d. Vaccines.

**3.  Patch Testing** is the gold standard method of identifying the cause of
allergic contact dermatitis.  This testing is indicated to evaluate a
nonspecific dermatitis, pruritus, to differentiate allergic contact dermatitis
(ACD) and irritant contact dermatitis (ICD) and determine the causative
antigen. It is a diagnostic test reserved for patients with skin eruptions for
which a contact allergy source is likely.

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 or 96 hours, and the reactions are
systematically 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.

Allergy patch testing is a covered procedure only when used to diagnose
allergic contact dermatitis after the following exposures:  dermatitis due to
detergents, oils and greases, solvents, drugs and medicines in contact with
skin, other chemical products, food in contact with skin, plants (except
food), cosmetics, metals, rubber additives, other and unspecified.  Patch
tests may also be used and may be helpful when a distribution and persistence
of dermatitis suggests a possible contact allergy, but the exact etiology of
the dermatitis is unknown.

The clinician should recognize that contact sensitization to metals or bone
cement that is used in orthopedic, cardiac, dental, and gynecological implants
has been associated with both dermatitis and noncutaneous complications. These
complications may include  
localized pain, swelling, erythema, warmth, implant loosening, decreased range
of motion, stent stenosis, and pericardial effusions in the case of cardiac
implants. Patch testing to implant or device components has been recommended
to help determine the etiology of the adverse reaction.

**4.  Photo Patch Testing** uses two patches, with one of them being
irradiated with ultraviolet light half way through the occlusive period. It is
indicated to evaluate unique allergies resulting from light exposure.  Some
chemicals or medications produce an allergic reaction only when exposed to
light (usually ultraviolet type A, UVA).  Patients who are over-sensitive to
light and those with a rash that appears on parts of the body normally exposed
to light but that does not appear in areas shielded from the light should have
a photo-patch test.

**5.**   **Photo Tests** is skin irradiation with a specific range of
ultraviolet light. Photo tests are performed for the evaluation of
photosensitivity disorders.

**6.  Skin Endpoint Titration (SET) Testing or Intradermal Dilutional Testing
(IDT)** analyzes the highest dilution of a substance that produces a reaction,
and may be used to determine the starting dose(s) of allergen immunotherapy.

**7.  Delayed Hypersensitivity Skin Testing** has been commonly used in three
ways: anergy testing, testing for infection with intracellular pathogens, and
testing for sensitivity to contact allergens. Accurate testing for contact
allergy requires careful attention to technique, and limitation of testing to
the specific allergens known to be associated with a contact reaction.

**8.  Ophthalmic Mucous Membrane Tests and Direct Nasal Mucous Membrane
Tests** are rarely indicated. They are allowed when skin testing cannot test
allergens.

Ophthalmic mucous membrane tests and direct nasal mucous membrane tests are
approved if levels of allergic mediators (such as histamine and tryptase) are
measured and a placebo control is performed. This is usually performed in
allergy research laboratories. It is also approved in the office setting if
the physician is there to observe objective measurement of reactions which
might include redness of the eyes, tearing and sneezing.

**9.  Inhalation Bronchial Challenge Testing** involves the inhalation of
agents that can trigger respiratory responses and are often used to evaluate
new allergens and/or substantiate the role of allergens in patients with
significant symptoms. Results of these tests are ordinarily evaluated by
objective measures of pulmonary function and occasionally by characterization
of bronchoalveolar lavage samples.

a. Inhalation bronchial challenge tests should be performed as dose-response
assays where in provocation concentration thresholds can be determined on the
basis of allergen concentration required to cause a significant decrease in
measured pulmonary function.  
b. Inhalation bronchial challenge tests with occupational allergens need to be
carefully controlled with respect to dose and duration of exposure. When
industrial small molecular weight agents are assessed, tests should be
performed under conditions of continuous monitoring of the specific chemical
being assessed so as not to exceed the threshold limit level permitted in the
workplace.

**10\. Ingestion (Oral) Challenge Test** involves the administration of
sequentially or incrementally larger doses of the test item. The test items
may include food or antibiotics. The service is allowed once per patient
encounter, regardless of the number of items tested, and includes evaluation
of the patient's response to the test items.

Challenge ingestion food testing is covered for the following indications:

 Food allergy, dermatitis  
 Anaphylactic shock due to adverse food reaction  
 Allergy to medicinal agents  
 Allergy to foods

Challenge Ingestion is not payable when used to diagnosis rheumatoid
arthritis, depression, or respiratory disorders. (CMS Pub. 100-03 _Medicare
National Coverage Determination (NCD)Manual,_ Chapter 1- Coverage
Determinations, Part 2 Section 110.12- Challenge Ingestion Food Testing).

**11.  Intracutaneous testing, delayed reaction** \- more than 6 tests, may be
covered but requires additional justification and case-by-case review for the
number of tests performed and the medical necessity except when the skin test
is used:

For collagen implant therapy. Refer to: CMS Pub 100-03 _Medicare National
Coverage Determinations (NCD) Manual, Chapter 1_ - Coverage Determinations,
Part 4, Section 230.10 - Incontinence Control Devices.

**12.  Organ challenge test** materials may be applied to the mucosae of the
conjunctivae, nares, GI tract, or bronchi. Considerable experience with these
methods is required for proper interpretation and analysis. All organ
challenge tests should be preceded by a control test with diluent and, if
possible, the procedure should be performed on a double blind or at least
single-blind basis.

**B. In vitro testing** (blood serum analysis):  immediate hypersensitivity
testing by measurement of allergen-specific serum IgE in the blood serum.
They are useful when testing for inhalant allergens (pollens, molds, dust
mites, animal danders), foods, insect stings, and other allergens such as
drugs or latex, when direct skin testing is impossible due to extensive
dermatitis, marked dermatographism, or in children younger than four years of
age.

In vitro testing is covered when skin testing is not possible or would be
unreliable; or in vitro testing is medically reasonable and necessary as
determined by the physician.   When in vitro testing is ordered or performed,
the medical record must clearly document the indication and why it is being
used instead of skin testing.

It is not covered when done in addition to a skin test for the same antigen,
except in the case of suspected latex sensitivity, hymenoptera, or nut/peanut
sensitivity where both the skin test and the in-vitro test may be performed.
The number of tests done, choice of antigens, frequency of repetition and
other coverages issues are the same as skin testing.

Testing must be based on a careful history/physical examination which suggests
IgE medicated disease.  Total Serum IgE is not appropriate in most general
allergy testing.  Instead, individual IgE tests are performed against a
specific antigen.

Special clinical situations in which specific IgE immunoassays are performed
against a specific antigen may be appropriate in the following situations:

1\. Patients with extensive dermatitis, severe dermatographism, ichthyosis or
generalized eczema that will not make direct skin testing possible.  
2\. Patients needing continued use of H-1 blockers (antihistamines), or in the
rare patient with persistent unexplained negative histamine control.  
3\. Patients who cannot be safely withdrawn from medications that interfere
with skin testing, such as long-acting antihistamines, tricyclic
antidepressants, beta-blockers, or medications that may put the patient at
undue risk if they are discontinued long enough to perform skin tests.  
4\. Uncooperative patients with mental or physical impairments.  
5.  For evaluation of cross-reactivity between insect venoms (e.g., fire ant, bee, wasp, yellow jacket, hornet).  
6.  As adjunctive laboratory testing for disease activity of allergic bronchopulmonary aspergillosis and certain parasitic disease.  
7.  To diagnose atopy in small children.  
8.  Patients at increased risk for anaphylactic response from skin testing based on clinical history (e.g., when an unusual allergen is not available as a licensed skin test extract), or who have a history of a previous systemic reaction to skin testing.  
9.  Patients in who skin testing were equivocal/inconclusive and in vitro testing is required as a confirmatory test.

Total IgE is reasonable and necessary for follow-up of Allergic
Bronchopulmonary Aspergillosis (ABPA) and to diagnosis atopy in children.

Retesting with the same antigen(s) should rarely be necessary within a three-
year period. Exceptions include young children with negative skin tests, or
older children and adults with negative skin tests in the face of persistent
symptoms. Routine repetition of skin tests is not indicated (i.e., annually)
and not covered.

**Limitations:**  
The following tests are considered not medically reasonable and necessary:

**1.  Ingestion (Oral) Challenge Food Testing** performed by the patient in
the home, and not in the office setting, will not be covered.

**2.  Provocative Testing** for which there is limited or no evidence of
validity include the cytotoxic test, the provocation-neutralization procedure,
electrodermal diagnosis, applied kinesiology, the "reaginic" pulse test, and
chemical analysis of body tissues. Controlled studies for the cytotoxic and
provocation-neutralization tests demonstrated that the results are not
reproducible and do not correlate with clinical evidence of allergy.
Electrodermal diagnosis and applied kinesiology have not been evaluated for
efficacy. Similarly, the "reaginic" pulse test and chemical analysis of body
tissues for various exogenous chemicals have not been substantiated as valid
tests for allergy.

Provocative and neutralization testing and neutralization therapy (Rinkel
test) of food allergies (sublingual, intracutaneous and subcutaneous) are
excluded from Medicare coverage because available evidence does not show these
tests and therapies are effective.

**3.  IgG and IgG Subclass Antibody Tests** measure allergen-specific IgG and
IgG subclasses by using immunoabsorption assays and IgG and IgG subclass
antibody tests for food allergy/delayed food allergic symptoms or intolerance
to specific foods.  These tests are considered experimental and
investigational since there is insufficient evidence in the published peer-
reviewed scientific literature to support the diagnostic value of these tests.

**4.  Antigens** for which no clinical efficacy is documented in peer reviewed
literature include the following:  newsprint, tobacco smoke and leaf,
dandelion, orris root, phenol, alcohol, sugar, yeast, grain mill dust, soybean
dust (except when the patient has a known exposure to soybean dust such as a
food processing plant), honeysuckle, marigold, goldenrod, fiberglass, wool,
green tea, or chalk.

**5.  Radioallergosorbent test (RAST), fluoroallergosorbent test (FAST), and
multiple antigen simultaneous test (MAST)** are in vitro techniques for
determining whether a patient's serum contains IgE antibodies against specific
allergens of clinical importance.   As with any allergy testing, the need for
such tests is based on the findings during a complete history and physical
examination of the patient. These tests are not appropriate in most general
allergy testing.  Instead, individual IgE tests should be performed against a
specific antigen.

**6.  ELISA (enzyme-linked immunoaorbent assay) test** is another in vitro
method of allergy testing for specific IgE antibodies against allergens.  It
is used to determine in vitro reaction to various foods and relies on
lymphocyte blastogenesis in response to certain food antigens.

**7.  Quantitative multi-allergen screen** is a non-specific screen that does
not identify a specific antigen. It is does not have sufficient literature
demonstrating clear cut clinical implication.  It is a screening tool and
therefore not covered by Medicare.

**8.**   **Cytotoxic leukocyte tests** are excluded. (CMS Pub. 100-03
_Medicare National Coverage Determination (NCD) Manual,_ Chapter 1- Coverage
Determinations, Part 2 Section 110.13-Cytotoxic Food Tests).

**9.**   **Sublingual intracutaneous and subcutaneous provocative and
neutralization testing and neutralization therapy for food allergies** are
excluded. (CMS Pub 100-03 _Medicare National Coverage Determinations_
_Manual,_ Chapter 1- Coverage Determinations, Part 2, Section 110.11 - Food
Allergy Testing and Treatment).

**10.  **The following tests are considered **experimental and investigational
for allergy testing** as these have not been proven to be effective or
appropriate for the evaluation and/or management of IgE-mediated allergic
reactions. This list is not all inclusive:

a. Antigen leukocyte cellular antibody (ALCAT) automated food allergy testing  
b. Applied kinesiology or Nambudripad's allergy elimination test (NAET (i.e.,
muscle strength testing or measurement after allergen ingestion)  
c. Anti-Fc epsilon receptor antibodies testing  
d. Anti-IgE receptor antibody testing  
e. Blood, urine, or stool micro-nutrient assessments  
f. Candidiasis test  
g. Chemical analysis of body tissues (e.g., hair)  
h. Chlorinated pesticides (serum)  
i. Chronic urticarial index testing  
j. Clifford materials reactivity testing  
k. Complement (total or components)  
l. Complement antigen testing  
m. C-reactive protein  
n. Cytokine and cytokine receptor assay  
o. Cytotoxic testing for environmental or clinical ecological allergy testing
(Bryans Test, ACT)  
p. Electrodermal testing or electro-acupuncture  
q. Electromagnetic sensitivity syndrome/disorder (allergy to electricity,
electro-sensitivity, electrohypersensitivity, and hypersensitivity to
electricity).  
r. Environmental cultures and chemicals  
s. Eosinophil cationic protein (ECP) test  
t. Food immune complex assay (FICA) or food allergenic extract immunotherapy  
u. General immune system assessments  
v. Immune complex assay  
w. Immunoglobulin G (IgG) testing for allergy  
x. Iridology  
y. Leukocyte antibodies testing  
z. Leukocyte histamine release test (LHRT)/basophil histamine release test  
aa. Lymphocytes (B or T subsets)  
ab. Lymphocyte function assay  
ac. Mediator release test (MRT) or the LEAP program  
ad. Metabolic assessments  
ae. Multiple chemical sensitivity syndrome (a.k.a., idiopathic environmental
intolerance (IEI), clinical ecological illness, clinical ecology,
environmental illness, chemical AIDS, environmental/chemical hypersensitivity
disease, total allergy syndrome, cerebral allergy, 20th century disease)  
af. Prausnitz-Kustner or P-K testing - passive cutaneous transfer test  
ag. Pulse response test  
ah. Qualification of nutritional assessments  
ai. Rebuck skin window test  
aj. Secretory IgA (salvia)  
ak. Sage Complement Antigen Test  
al. Specific Immunoglobulin (IgG) (e.g., by Radioallergosorbent (RAST) or
Enzyme-linked immunosorbent assay (ELISA)  
am.Sublingual provocative neutralization testing and treatment with hormones.  
an.Total serum IgG, immunoglobulin A (IgA) and immunoglobulin M (IgM  
ao. Venom blocking antibodies  
ap. Volatile chemical panels (blood testing for chemicals)  
aq. Live Cell Analysis  
ar. Passive Transfer  
as. Cytotoxic Food Testing

Routine allergy re-testing does not meet the definition of medically necessity
according to the practice parameters and recommendations from the American
College of Allergy, Asthma, and Immunology (ACAAI), the American Academy of
Allergy, Asthma, and Immunology (AAAAI), and the Joint Council of Allergy,
Asthma, and Immunology (JCAAI).