For allergy sufferers, spring is the season that signals the return of sneezing, a runny nose, and itchy eyes. Antihistamines, decongestants, and nasal steroid sprays provide a reprieve from seasonal allergy symptoms, but they may have undesirable side effects like drowsiness. Some people turn to allergy shots, or subcutaneous immunotherapy, for long-lasting symptom relief.
Until recently, undergoing immunotherapy meant traveling to your allergist’s office for weekly injections of a custom-made solution for several months and then getting monthly maintenance shots for three to five years. In 2014, the U.S. Food and Drug Administration (FDA) approved a needle-free immunotherapy for hay fever for adults, but only up to age 65.
Sublingual immunotherapy (also called SLIT), involves placing a tablet that rapidly dissolves under your tongue each day for several months of the year. A welcome benefit of sublingual immunotherapy is that you can do it yourself at home and no longer have to travel.
“While allergy shots are effective, going to the doctor’s office once or twice a week for an extended period can be difficult to keep up with,” says Lee M. Akst, M.D., director of the Johns Hopkins Voice Center and assistant professor of medicine at Johns Hopkins University School of Medicine in Baltimore. “For people who don’t have time for regular doctor appointments—or who find allergy shots too unpleasant—the convenience of tablets may be a good option. Because the tablets have less risk of severe allergic reaction than shots, they can be safely self-administered at home.”
Like allergy shots, sublingual immunotherapy works by helping you build up resistance to the allergen so symptoms no longer bother you. One downside of sublingual tablets is that they’re not for everyone.
The drugs work for only grass and ragweed allergies, not tree allergies. Plus, the tablets are formulated to treat only a single allergy, so if you’re allergic to multiple allergens, sublingual immunotherapy may not work as well for you as shots. You also should avoid sublingual immunotherapy if you have uncontrolled or severe asthma or have had past severe allergic reactions.
The FDA has approved three sublingual tablets that have shown effectiveness in clinical trials for people up to age 65 with hay fever or allergic rhinitis:
• Oralair for five kinds of northern grass pollen (timothy, orchard, perennial rye, Kentucky blue grass, sweet vernal)
• Grastek for timothy grass pollen
• Ragwitek for short ragweed
You’ll get your initial dose in the allergist’s office, where you’ll be observed for about 30 minutes for signs of severe allergic reactions, such as anaphylaxis, which causes the airways to tighten. With sublingual immunotherapy, though, anaphylaxis is extremely rare, making it safer than allergy shots.
Still, you’ll be advised to keep a epinephrine auto-injector (EpiPen) on hand in case you have an adverse reaction. Other potential side effects—which typically subside after the first few doses—include itching and swelling in the mouth and throat irritation.
How sublingual immunotherapy works
You should start sublingual immunotherapy treatment 12 to 16 weeks before allergy season. You’ll take one tablet a day until allergy season ends and repeat this regimen for three to five years. You’ll likely continue to take your allergy meds or sprays and taper them off as your symptoms improve.
“Your symptoms should improve within the first three to four months of starting SLIT,” Akst says. “You must remember to take tablets consistently every day, however; missing several doses might reduce the therapy’s potency.”
According to the American College of Allergy, Asthma, and Immunology, it could take three to five years of treatment to develop an immunity, a duration similar to that of injection therapy. Other research suggests that relief lasts at least one or two years after treatment ends. Studies have found that sublingual immunotherapy relieved allergy symptoms as well as most other remedies.
Studies directly comparing sublingual immunotherapy with shots are sparse, but a 2014 review in the Journal of Allergy and Clinical Immunology: In Practice reported that both therapies had similar effectiveness. A 2013 review also found that both therapies were effective, but due to lack of evidence, the researchers couldn’t show that one was better than the other. Other studies have had mixed results, with injections often having the edge over sublingual immunotherapy. For long-lasting immunity, the number of years sublingual immunotherapy needs to be administered isn’t clear; further research is needed.
Health insurance typically doesn’t cover sublingual immunotherapy, and a month’s supply of tablets can cost nearly $400. All three drug manufacturers offer discount coupons on their websites for eligible candidates.
A daily dose in a drop
Under-the-tongue drops formulated to treat multiple allergens have been approved for use in some European countries. Formulations of drops are under review by the U.S. Food and Drug Administration and not yet approved for use.
However, some allergists here are prescribing custom-mixed drops produced with the same allergen extracts used in allergy shots. This practice is considered an “off-label” drug use.
More studies are needed before this practice can be considered safe and effective, although research so far has indicated that it’s as safe as tablets. But, since the drops are being used off-label, they’re not covered by insurance or Medicare.