New Help for Allergy Sufferers: How Does Sublingual Immunotherapy Work? – Part 2


Sublingual immunotherapy is an increasingly popular treatment for seasonal and other allergies. How does it work?

Intended to prevent and treat disease or allergen-caused conditions, immunotherapy introduces material (like a germ or an allergen) to the human immune system to provoke an ultimately helpful response. It functions similarly to vaccines, which can protect you against certain viruses or bacterial infections.

In an earlier post, we discussed types of allergen-specific immunotherapy (ASI) like subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).

For those who suffer chronic seasonal allergies, or mild asthma, ASI has numerous advantages that include:

  • Better, more comfortable quality of life
  • Reduction of symptoms related to allergic rhinitis and allergic asthma
  • Decreased reliance on medications like antihistamines, decongestants, and nasal sprays

How does Immunotherapy Work?

Allergen-specific immunotherapy works by desensitizing your system to the allergens that causes your symptoms and discomfort.

As part of the immunotherapy process, you undergo testing, using skin-prick tests or lab work, to identify the specific allergens causing your allergic response. Unlike medications aimed at managing general allergy symptoms, testing focuses on finding the cause.

Creating a clinical history is part of ASI, to ensure you are a good candidate for treatment. Talk to your doctor about the advisability and safety of allergen immunotherapy under conditions such as:

  • A patient under five years of age
  • Pregnancy, or potential pregnancy
  • Presence of severe allergies, strong allergic reactions, or average to severe asthma
  • Underlying medical conditions, or taking certain medications

What about Sublingual Immunotherapy?

Once specific allergens are identified, you have a choice of treatments including lifestyle changes, medication, allergen avoidance, SLIT, or SCIT.

SLIT and SCIT are therapies developed to address the problem, not mask the cause. By desensitizing your immune system to specified allergens, your symptoms are reduced.

Whether you receive injections, or take tablets or drops, you receive small amounts of the allergens causing your symptoms. It may sound backward, but it works. Here is the process with SLIT:

  • After placing a tablet or drops under your tongue, the extract dissolves and is absorbed through the mucous membrane in your mouth, with few side effects. Any residue of a tablet is swallowed and makes its way to the small intestine.
  • Throughout the duration of treatment, the daily dose of allergens causes changes in cellular activity to reduce local inflammatory reaction to the allergen, and blunt the build-up of symptoms during active exposure (allergy season).

SLIT and SCIT work similarly to achieve the same goal. Because the delivery mechanisms are different, so is your experience. Consider these differences:

  • Delivery: Subcutaneous injections – allergy shots — are usually given weekly, at the office of your physician for the first year. The initial dose of a sublingual extract is given at the doctor’s office, thereafter, once a day at home. Over time, the amount of allergen in each dose is increased to reach a target or maintenance level dose.
  • Duration: Treatment by injection or extract is generally given over a three to five-year period. Improvement in symptoms may occur within, or after the first year of treatment. Many patients drop out of treatment before it is concluded. With the relatively convenient, painless delivery of SLIT, busy patients can maintain their health—and their schedule.
  • Side effects and safety: Side effects of SCIT may be similar to the allergy itself—coughing, headache, fatigue, sneezing, and redness, pain, or itch at the site of injection. SLIT can cause throat irritation or mild itching or swelling in the mouth. Though rare, both modalities can trigger anaphylaxis, a life-threatening allergic response.
  • Effect and benefits: Both SLIT and SCIT are considered effective. At present, research studies do not find either treatment more effective than the other. Long term benefits of allergen-specific immunotherapy include cessation or reduction of symptoms, potential avoidance of onset of allergic asthma, or more serious allergic reactions.
  • Cost: Currently, many health insurance companies reimburse for the cost of SCIT for allergy relief, excluding co-pays. Because approval of sublingual extract tablets was not approved by the U.S. Food and Drug Administration (FDA) until 2014, some insurance companies do not yet reimburse for SLIT.

Already in use in European countries, expanded use of sublingual extracts and tablets offers Americans an effective, easy alternative to improve their health—and quality of life.

If you have questions about sublingual immunotherapy in the New York metro area, contact my office for more information.

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