Tired of Popping Antihistamines? Try These Long-Term Allergy Therapies
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.
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 American College of Allergy, Asthma, & Immunology (ACAAI), some people find the medications don’t work as well even as the season goes on, or as their allergies change.
You can try different types of medications, or even step up your dosage, but eventually it can get to where the side effects are just too difficult to deal with—or you’re not getting the relief you hoped for.
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.
Even more concerning: a recent study found compelling evidence of a link between long-term use of “anticholinergic” allergy medications like Benadryl and dementia. The researchers tracked medical data from nearly 3,500 participants 65 and older for about seven years. They found that people who used the drugs were more likely to develop dementia than those who didn’t. Taking the drugs for three years or more was also associated with a 54 percent higher dementia risk than taking them for three months or less.
As climate change seems to be making allergies worse (studies have shown that rising temperatures and higher carbon dioxide levels make the pollen season longer and more severe), women are searching for solutions. If long-term use of antihistamines isn’t a good idea, what are our alternatives?
Allergen Immunotherapy (Allergy Shots)
Considered the gold standard for long-term allergy treatment for decades, allergy shots—or allergen-specific immunotherapy, as it’s called in medical circles—can help significantly improve symptoms and reduce the need for medication. It can also protect against the development of other allergies and symptoms down the road.
This type of therapy changes the immune system’s response to an allergen. The reason we suffer from allergy symptoms in the first place is because the immune system mistakenly sees the “invader” or allergen as a threat, and mounts a defense against it. Part of that defense includes releasing histamines into the blood stream, which cause standard symptoms like runny nose, itchy eyes, hives, stomach upset and difficulty breathing.
Allergy shots are sometimes called “allergen vaccines,” as they help the body get used to the trigger so that the patient no longer experiences the out-of-control immune reaction. The allergy doctor first tests the individual to find what she’s allergic to, and then develops a customized therapy that exposes the body to increasingly higher doses of the actual allergy trigger until the body becomes resistant to it.
The key here is that the body becomes resistant, and once that happens, the patient no longer needs medications, because the symptoms don’t occur. In fact, allergen-specific immunotherapy is the only type of allergy treatment that keeps working after you stop taking it.
Do Allergy Shots Work?
A number of studies have shown that this treatment is very effective. A 2013 analysis of eight studies, for example, reported that a three-year treatment with allergy shots provided at least three years of subsequent relief of symptoms.
An earlier 2011 study reported that long-term effects of immunotherapy included a reduction in nasal symptoms, an decrease in the use of medications, and an improvement in quality of life. And a 2012 study reported that allergen-specific immunotherapy was the only treatment that changes the body’s response to allergens, and therefore helped not only treat current allergies, but prevent future ones.
If you have allergies every year and medications are no longer working or you don’t want to use them long-term, allergy shots may be the answer. My mom took them for years, and they weren’t as scary as you may think. The needle is very small and usually not bothersome.
It can take a considerable time commitment to get to the allergy office one or more times a week for shots, however, until the “build-up” phase is complete (lasting usually 3-6 months, after which the “maintenance phase” begins, where shots are needed only once every 2-4 weeks.) Are there other options?
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.
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.
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