I’ve taken antihistamines practically all my life, it seems. It started out in high school when I was running cross-country. One afternoon, after a mile sprint, I started having difficulty breathing. My throat closed about halfway and one eye swelled shut. I begged off practice and drove home in a panic.
When I walked in the door I was feeling a little dizzy and wheezing loudly. Fortunately my mom knew was going on and brought a Benadryl to the rescue. We went to the allergy doctor, but by the time we got there I was feeling better. Though I was sleepy, I became a fan of the antihistamine that day, as it felt like it had saved my life.
Estimates are that about one in five people in the U.S. have either allergy or asthma symptoms, and over half test positive to one or more allergens. For me it was weeds and trees, but the triggers are varied and numerous, ranging from pollen to flowers to ragweed, dust, pet dander and more.
Some allergy experts recommend avoiding long-term use of antihistamines, because they mask the problem, and combined with decongestants, can actually cause a rebound effect that make symptoms worse.
Many of us turn to over-the-counter antihistamines to help. They tend to be fairly effective, but they can have troublesome side effects, including dry eyes, sleepiness, constipation, dry mouth, and blurred vision.
Antihistamines can also become less effective over time. According to the
Sublingual Allergy Drops or Tablets
Called “sublingual immunotherapy,” or “SLIT,” this is essentially the same treatment as allergy shots, without the needle. Instead, the doctor gives you small doses of the allergens under your tongue. They’re absorbed into the body and the idea is the same—over time, you build up a resistance.
This is a fairly new approach to immunotherapy, and so far, the only forms of SLIT that have received FDA approval are tablets for ragweed and grass pollen. There are allergy “drops,” however, that can be used to help the body build up a tolerance. So far, the FDA hasn’t approved any for this purpose, but your doctor can still prescribe them “off-label” for treatment.
Called “sublingual immunotherapy,” or “SLIT,” this is essentially the same treatment as allergy shots, without the needle. Instead, the doctor gives you small doses of the allergens under your tongue.
The process is much the same as that for allergy shots. Your doctor tests you for allergens, and then formulates a custom-mix of drops (or tablets) containing allergen extracts to administer regularly over time. You simply hold the drops or tablet under your tongue for a minute or two and then swallow.
The good news about this type of treatment is that you can do it at home instead of having to go to the doctor’s office every week (or every few weeks). That’s a huge advantage for busy women, and one that makes this type of therapy very attractive.
Does it work as well as shots? The ACAAI states that most clinical trials published over the past 20 years show that it’s safe and effective for rhinitis and asthma caused by dust mites, grass, ragweed, cat dander, and tree pollens. New research has also suggested that it may work well for treating red, itchy eyes during hay fever season, and for helping children with eczema.
Some individual studies showing benefits include:
- 2013: A “position paper” published in the World Allergy Organization Journal reported that several large definitive trials have confirmed the safety and efficacy of SLIT for seasonal rhinitis in both children and adults. Long-term benefits have been found to last at least one-to-two years after treatment is over.
- 2013: A systematic review of 63 studies showed strong evidence that SLIT improves asthma symptoms and moderate evidence that it decreases rhinitis symptoms.
- 2015: A literature review shows that SLIT actually seems to be safer than allergy shots (fewer potential side effects), and lists a number of studies showing the treatment to provide a 20 to 50 percent improvement in symptoms, with most patients experiencing benefits for at least one-to-two years after the end of treatment
What is the Future of Long-Term Allergy Treatment?
Currently, the only methods we have for long-term allergy treatment are shots, drops, and tablets.
So we wondered—is there anything new on the horizon?
Scientists are looking into it, and so far, are coming up with some exciting results. One of the methods they’re trying is to use nanoparticle technology to carry allergens past the immune system so it learns not to attack them.
In a 2016 study, for example, researchers from Northwestern University introduced an allergen-loaded nanoparticle into the bloodstream of mice. Because the nanoparticle was composed of material including lactic acid and glycolic acid, the immune system paid it no mind. The particle was consumed by a macrophage—an immune cell responsible for clean-up—helping to reset the immune system to recognize the allergen as non-threatening.
After being exposed to the nanoparticle, the mice no longer had an allergic response to the allergen. Senior author Stephen Miller reported that the results represent “a novel, safe, and effective long-term way to treat and potentially ‘cure’ patients with life-threatening respiratory and food allergies.”
The technology is now proceeding to human clinical trials.
“Allergy Statistics and Facts,” WebMD, /allergies/allergy-statistics.
“Allergic Rhinitis,” ACAAI, /article.aspx?articleid=2091745.
Franco Frati, et al., “Long-Term Efficacy of Allergen Immunotherapy,” Immunotherapy, 2013; 5(2):131-133, /viewarticle/781208.
Eifan AO, et al., “Long-term clinical and immunological effects of allergen immunotherapy,” Curr Opin Allergy Clin Immunol., December 2011; 11(6):586-93, /articles/10.1186/1939-4551-7-6.
Lin SY, et al., “Sublingual immunotherapy for the treatment of allergic rhinoconjunctivitis and asthma: a systematic review,” JAMA, March 27, 2013; 309(12):1278-88, /contents/sublingual-immunotherapy-for-allergic-rhinoconjunctivitis-and-asthma.
Charles B. Smasrr, et al., “Biodegradable antigen-associated PLG nanoparticles tolerize Th2-mediated allergic airway inflammation pre- and postsensitization,” PNAS, May 3, 2016; 113(18):5059-5064, http://www.pnas.org/content/113/18/5059.