Immunotherapy via subcutaneous injection

Immunotherapy can be given either by subcutaneous injection, called subcutaneous immunotherapy (SCIT), or drops held under the tongue at home, called sublingual immunotherapy (SLIT).

Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.
Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.

Sublingual immunotherapy (SLIT) works in the same way as SCIT by altering the immune system and thus greatly improving allergic rhinitis and allergic asthma. Sublingual immunotherapy has been used in Europe for about 15 years and has the advantage of being able to be given at home. About half of patients requiring allergy immunotherapy in Europe receive it sublingually rather than subcutaneously by injection.

Subcutaneous immunotherapy (SCIT) has been used in difficult cases of allergic rhinitis and allergic asthma for almost 100 years. It has been improved by using more concentrated allergy extract with multiple medical studies showing the exact effective dose. A timed-release form of SCIT extract is available to reduce local swelling at the injection site. If inhaled allergens are causing nasal allergy or asthma, it is effective in about 90% of patients and generally results in long-term remission once allergy injections are discontinued. For further information on SCIT, click to the right on "Allergy Shots".

Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.

Although they accomplish the same thing as far as improving inhalant allergy, there are pros and cons to both SLIT and SCIT. The pros to SLIT are that it can be safely taken at home with only the first dosage given in Dr. Scott's office. It is given daily, 5 drops under the tongue. By day 30, you have increased the dosage to a full top-maintenance dosage. There can be some minor itching under the tongue but only rare serious allergic reactions have occurred, and there have been no deaths due to SLIT reported. Another advantage to SLIT is that there is no shot given. Some patients can be fairly needle-phobic and prefer the drops. Others have jobs that just don't allow them to come to a physician's office for weekly and, later, monthly subcutaneous allergy injections.

Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.

The cons to sublingual immunotherapy are that the allergy extract does not have approval by the FDA for use under the tongue. For the allergy extract manufacturers to do these studies for each individual allergen, such as sagebrush pollen, alternaria mold and cat dander would be cost prohibitive. Insurance companies will not pay for anything that is not FDA approved. This means they will not pay for allergy extract administered under the tongue, but they do routinely pay for SCIT. We are able to provide SLIT allergy drops at our cost by preparing them on a cash only basis, requiring the payment in advance. If you have further interest in SLIT, please click below for general information from our office, as well as dosing schedules.

Sublingual Immunotherapy (SLIT/Allergy Drops) Overview

Sublingual immunotherapy (SLIT/Allergy Drops) is the name given to allergy extract that is administered orally. The allergy extract, rather than being administered by an injection, is administered as oral allergy drops that are placed under the tongue ("sublingual"), held there for two minutes, and then swallowed. Sublingual immunotherapy is a unique type of immunotherapy that combines safety and convenience with excellent efficiency. Popular in Europe for many years, sublingual immunotherapy is now being introduced into the United States and is gaining in popularity. Many patients prefer allergy immunotherapy because it treats the cause of inhalant allergies/asthma rather than merely treating the symptoms with medications.

Advantages of SLIT Therapy

Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.
Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.

Advantages of sublingual immunotherapy include a safety profile that allows the treatment to be administered at home, saving the patient travel time and expense. The lack of injections makes sublingual immunotherapy easier for some patients to tolerate the treatment. It is also an ideal treatment for patients who travel frequently or who live a long distance from a medical facility or have a work schedule that does not allow time to take injections in a physician's office and then wait the required 30 minutes afterward.

Disadvantages of SLIT Therapy

Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.
Allergy and asthma treatment, Allergy and Asthma Center of Western Colorado, Grand Junction, Colorado.

The primary disadvantages of sublingual immunotherapy center around two facts:

(1) Although SLIT accounts for more than half of all allergen immunotherapy administered in Europe, it is currently considered "investigational" and "off-label" in the United States. Even though the allergen extracts that are used for subcutaneous (injection) immunotherapy (SCIT) and for sublingual immunotherapy (SLIT) are the same, and are licensed for use in the United States for SCIT, the FDA has not yet approved the extracts for SLIT. For this reason there is no current billing code for the SLIT treatments.

(2) Because of this "off-label" status for sublingual immunotherapy, insurance companies are not currently reimbursing this form of treatment, making the expense "out-of-pocket" to the patient. Nevertheless, the overall cost of SLIT is significantly less than a lifetime of allergy medications and office visits for allergy-related illnesses and is less than the overall cost of receiving subcutaneous (injection) immunotherapy. We anticipate that this insurance reimbursement issue will improve in coming years, as the FDA is currently looking at several sublingual allergy extract products for potential approval.

Patients ask if all allergy drop procedures are equal, and the answer is a definite NO! There are numerous SLIT clinics and companies that offer low dose sublingual  immunotherapy and is often only a placebo treatment. Allergy extract is quite expensive and so there is unfortunately an incentive to use low doses of extract. For SLIT to be as effective as it is in trials, high concentrations need to be used. 

Our clinic offers targeted high-dose oral immunotherapy treatments, designed in accordance with well established European protocols that have been shown to offer excellent benefit. The current studies still indicate that injection immunotherapy may be slightly more beneficial, but oral immunotherapy offers substantial benefits much greater than placebo drops in controlled medical studies. Because of the convenience of home therapy and good efficacy, SLIT is rapidly being used more for airborne allergies (pollen, mold, dust mites, and animal danders).