Accelerated Subcutaneous Immunotherapy: Should You Provide It in Your Practice?

Gary J. Stadtmauer, MD


April 03, 2015

Immunotherapy for Respiratory Allergies

Subcutaneous allergy injection therapy (SCIT) has been used to successfully treat respiratory allergy for more than a century. What has changed is the availability of other medications, including the recent availability in the United States of oral immunotherapy. Patients presenting to the allergist's office today may very well have already tried some of the best medications we have available to treat allergic rhinitis and conjunctivitis, including over-the-counter (OTC) nasal steroids, OTC nonsedating antihistamines, or OTC ocular antihistamines. There are only a few more remedies to try (eg, leukotriene modifiers and nasal antihistamines) before the conversation progresses to a discussion of immunotherapy.

Oral immunotherapy is an option for a selected group of patients whose major symptoms are restricted to one season. It is expensive and covers a selected range of pollens. SCIT has the benefit of customization for each patient. However, SCIT requires a commitment of time (3-8 months until the maintenance dose is achieved); during this build-up phase, patients usually remain symptomatic and sometimes drop out during this so-called trial period of SCIT.

A way to circumvent these problems is to pursue an accelerated allergen immunotherapy schedule with either the cluster or the rush approach, techniques that involve giving patients successive doses of allergy injections on the same day. Cluster SCIT is the more graduated of the two approaches, with the patient achieving maintenance over a few weeks. Serial allergy injections are given on the same day, and the patient returns the following week for the next series until maintenance is reached in about 4-8 weeks. Rush immunotherapy (RIT) can achieve maintenance in a matter of a days, if not hours (known as "ultrarush immunotherapy"). These techniques have been applied for environmental allergens and venoms.

Safety and Efficacy of Rapid Approaches

The efficacy of the cluster and rush approaches is well established and has been reviewed elsewhere.[1] These approaches are comparable to traditional SCIT. The safety of cluster SCIT is not thought to be much different from conventional SCIT, although most of the studies comparing the safety of cluster schedules with conventional schedules use single allergens.[2]

Nothing is faster than RIT to get the patient to the maintenance dose, but the disadvantage of this approach is a higher frequency of systemic allergic reactions. Still, with premedication and careful patient selection, RIT may be the optimal choice for many patients. Premedication before RIT reduces systemic reactions,[3] and the vast majority of allergic reactions during RIT are mild; the most common reaction is flushing.[4]

Rationale for Instituting Accelerated Immunotherapy

The dropout rate from conventional SCIT has been reported as approximately 12% in one study,[5] and very few of these dropouts were for medical reasons. Those patients might be recaptured with a less cumbersome approach to immunotherapy. Many more patients who would not even consider a conventional SCIT schedule may opt for a cluster or rush approach owing to convenience and cost. The income potential is substantial.

Billing for Accelerated Immunotherapy

The buildup phase of cluster SCIT or RIT is usually as "rapid desensitization" (Current Procedural Terminology [CPT] code 95180) billed as 1 unit per hour. This code applies to clinical situations in which multiple injections of antigens are administered over a few hours at 30- to 120-minute intervals.

Medicare reimbursement for CPT 95180 is about $150 per hour. Insurance companies may limit the number of units per day (eg, a maximum of 4 hours). Because delayed reactions can occur up to 2 hours after the last injection during RIT, patients are often observed for that period of time. Each desensitization session is an office visit (CPT codes 99213, 99214, or 99215) and requires preparation of allergy serum (CPT code 95165).


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