How Sublingual Immunotherapy Works

Sublingual immunotherapy, also called allergy drops, works similar to allergy shots by gradually helping your body build tolerance to the substance(s) that cause your allergies. The difference is that the antigen is placed under your tongue in a liquid form.

The area under the tongue is has the highest concentration of antigen/allergen presenting cells found in the body. This cell, called the dendritic cell, is the messenger that delivers antigens to the cells that enable allergy tolerance. By delivering daily allergy drops consistently to this cell, the body begins to tolerate things that cause allergic reactions.

We recommend patients take allergy drops three times each day for three to five years. This may vary according to the severity and seasonality of their allergies, and how well people follow treatment guidelines. Many people feel better within a few months, but continuing treatment is necessary to help you stay symptom-free after your allergy drop treatment is complete.

Sublingual Immunotherapy and IgE

While many long-term studies of patients on sublingual immunotherapy have shown a decrease in specific IgE in some groups, not everyone’s IgE decreases. It is important to reinforce that IgE is only one measure of allergic response.

Just as IgE can be used to indicate allergic sensitivity, it can also be a late indicator of tolerance to allergens. Immunotherapy induces the regulatory T cell, the immune cell that regulates allergic inflammation. The T cells direct the cells that make immunoglobulin, B-cells, to make protective antibodies such as IgA and IgG4. With all of this immune stimulation, the IgE may actually increase in the first year of sublingual immunotherapy treatment before it decreases. Sometimes a ratio of IgE to IgG4 is used to indicate whether immune tolerance is developing.