Summary Of Evidence

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Analysis of Evidence

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Abstract:

Allergen immunotherapy is defined as the repeated administration of specific allergens to patients with IgE-mediated conditions, for the purpose of providing protection against the allergic symptoms and inflammatory reactions associated with natural exposure to these allergens.

Immunotherapy (hyposensitization) may extend over a period of years, usually on an increasing dosage scale. This is followed by a build-up of tolerance to the antigen (as evidenced by the markedly higher doses that can be administered) and a decline in the symptoms and medication requirements of the patient. Indications for immunotherapy are determined by diagnostic testing appropriate to the individual needs of each patient and his/her clinical history of allergic diseases.

Allergen immunotherapy should be differentiated from the process of desensitization, which usually applies to the rapid progressive administration of an allergenic substance to render effector cells less reactive.

The technique of allergen immunotherapy should also be differentiated from unproven techniques such as neutralization-provocation therapy. Optimal dosing for sublingual swallow and oral immunotherapies is under clinical investigation in the United States but remain investigational at this time.

This LCD documents CGS indications and limitations of coverage for these procedures

Indications:

Indications for immunotherapy are determined by appropriate diagnostic procedures coordinated with clinical judgment and knowledge of the natural history of allergic diseases.

Controlled studies have shown that allergen immunotherapy is effective for patients with allergic rhinitis or conjunctivitis, allergic asthma, and stinging insect hypersensitivity.

Allergen immunotherapy is indicated for patients who show demonstrable evidence of specific IgE antibodies to clinically relevant allergens and whose allergic symptoms warrant the time and risk of allergen immunotherapy. The necessity of initiating allergen immunotherapy may also depend on the degree to which symptoms can be reduced by medication, the amount and type of medication required to control symptoms, and whether appropriate avoidance is possible.

Allergen immunotherapy is indicated for patients with a diagnosis of allergic asthma, allergic conjunctivitis, allergic rhinitis, or stinging insect hypersensitivity depending on the results of allergy testing (immediate hypersensitivity skin tests or in vitro tests for specific IgE). There is limited data indicating that it may be effective in atopic dermatitis when this condition is associated with aeroallergen sensitivity. Immunotherapy should not be given to patients with negative results for specific IgE antibodies or those with positive test results for specific IgE antibodies that do not correlate with suspected triggers, clinical symptoms, or exposure. Immunotherapy is effective for pollen, mold, animal allergens, cockroach, and dust mite.

Venom immunotherapy is indicated for patients who have anaphylaxis after an insect sting and a positive skin test or other documented IgE sensitivity to specific insect venom. Patients with delayed systemic reactions with symptoms of anaphylaxis or serum sickness and with a positive skin test or presence of venom specific IgE by in vitro testing are also recommended for treatment.

Rapid desensitization is indicated in cases of allergy to insulin, penicillin and horse serum, as well as sulfonamides, cephalosporins and other commonly used drugs. In patients with a positive history of reaction and with documented skin test reactivity, every effort should be made to avoid the use of these substances. When circumstances require the use of one of these substances, the patient will have to be desensitized. Full-dose therapy should be initiated immediately after reactions (treated and controlled), requiring strict physician monitoring in a setting with continuous monitoring of vital signs and cardio-respiratory status. In most cases, this can be performed in a physician’s office if a physician trained to treat anaphylaxis is physically present for the entire duration. In cases where the initial reaction was severe, desensitization should be performed in the ambulatory care department of a hospital.

Desensitization may need to be repeated if future circumstances require an additional course of the offending allergen. Rapid desensitization in the form of rush immunotherapy may also be appropriate for venom, pollen, dust mite, mold and dander.

Standardized dust mite extracts appear effective for immunotherapy. Other environmental allergens (e.g., kapok, jute, feathers, and unstandardized house dust extracts) are of questionable value in immunotherapy, however, and generally should not be used.

Animal dander sensitivity (epidermal) may respond to immunotherapy. While removal of the offending allergen is recommended, this is often not possible or there may be occupational or other sources of exposure. Therefore, a trial of immunotherapy may be warranted.

Allergen-induced asthma is an indication for immunotherapy along the guidelines for allergic rhinitis when there is a poor response to environmental control or pharmacologic treatment.

Limitations:

Allergen immunotherapy is divided into codes that describe the injection only and codes that describe the preparation of the antigen to be delivered for injection by a different physician.

SUPPLY OF ANTIGEN

Payment may be made for a reasonable supply of antigens that have been prepared for a particular patient when:

• The antigens are prepared by a physician who is a doctor of medicine or osteopathy; and
• The physician who prepared the antigens has examined the patient and has determined a plan of treatment and a dosage regimen.

Antigens must be administered in accordance with the plan of treatment and by a doctor of medicine or osteopathy or by a properly instructed person under the supervision of the doctor.
Effective January 1, 2001, the Centers for Medicare and Medicaid Services (CMS) revised the regulation limiting the supply of antigens that can be prepared by a physician for a particular patient at one time. The limitation is changed from a 12-week supply to a 12-month supply. This regulation is revised with the stipulation that it is a physician's responsibility to furnish only a supply that would remain stable and potent over the time period for which they are administered.

TREATMENT SCHEDULES

The starting dose of an allergenic extract and the progression of the dose must be individualized for each patient. The Immunotherapy build-up schedule entails administration of gradually increasing doses during a period of approximately 14 to 28 weeks. In conventional schedules a single dose increase is given on each visit, and the visit frequency can vary from 1 to 3 times a week. Accelerated schedules such as rush or cluster immunotherapy entail administration of several injections at increasing doses on a single visit. Accelerated schedules offer the advantage of achieving the therapeutic dose earlier but might be associated with increased risk of systemic reaction in some patients.

LENGTH OF THERAPY

The duration of all forms of immunotherapy must be individualized. A presumption of failure can be made when, after 12-24 months of therapy, a person does not experience a noticeable decrease of symptoms, an increase in tolerance to the offending allergen and a reduction in medication usage.

Treatment will not be reimbursed after a 2-year period when there is no apparent clinical benefit.

The major risk of allergen immunotherapy is anaphylaxis. Allergen immunotherapy should, therefore, be administered under the supervision of an appropriately trained physician who can recognize early symptoms and signs of anaphylaxis and administer emergency medications where necessary. In addition, immunotherapy should be administered only in facilities equipped to treat anaphylaxis.

It may be appropriate to permit patient self-administration at home for the rare patient with life-threatening anaphylaxis who cannot receive immunotherapy in a health care facility (e.g., venom immunotherapy for a patient living in a remote area)). This requires very careful consideration of potential benefits and risks and should be made on an individual patient basis with appropriate informed consent.

The following services are considered investigational and will not be covered.

• Desensitization with commercially available extracts of poison ivy, poison oak, or poison sumac.
• Desensitization for hymenoptera sensitivity using whole body extracts, with the exception of venom extracts and fire ant extracts.
• Desensitization with bacterial vaccine (BAC: bacterial, antigen complex, streptococcus vaccine, staphylo-strepto vaccine, serobacterin, staphylococcus phage lysate).
• Food allergenic extract immunotherapy.
• Intracutaneous desensitization (Rinkel Injection Therapy, RIT).
• Neutralization therapy (intradermal and subcutaneous).
• Repository emulsion therapy.
• Sublingual desensitization.
• Sublingual provocative therapy.
• Urine autoinjection (autogenous urine immunotherapy).
• Allergen immunotherapy for the management of skin and mucous membrane disease such as urticaria, and Candida vulvovaginitis.

Patients who are mentally or physically unable to communicate clearly with the allergist and those with a history of noncompliance are not good candidates for allergy immunotherapy.

Medicare will not cover antigens provided for sublingual administration. This type of therapy has not been proven safe and effective.

Immunotherapy with whole-body extracts of biting insects or other arthropod (95170) is covered only for fire ant extracts.

Evaluation and management codes are separately reimbursable on the same day as allergen immunotherapy only when a significant, separately identifiable service is performed.