Now that it’s almost summer, chances are you’ve already had a run-in with allergies. The sneezing, the itching, the watery eyes, the snot (oh man, the snot); they’re all symptoms of what’s known as allergic rhinitis. It can be triggered by airborne outdoor allergens like mold and grass pollen as plants start to bloom in the spring, but indoor irritants like pet dander and dust mites can set off a round of sneezing year-round too.
Allergic rhinitis affects between 10 to 30 percent of people in the US and other industrialized countries, and there are a wide variety of over-the-counter medications to treat it. You can’t turn on the TV this time of year without seeing an ad for one antihistamine or another. But while the common oral medications like Claritin or Zyrtec do improve most symptoms, they don’t help with nasal congestion, or a stuffy nose, which most patients say is their main problem. Some nose sprays like Afrin do help with congestion, but can actually make it worse if used for more than 3 to 5 days; other, more effective nose sprays require a prescription and may have an odd smell or bitter taste.
Given the disconnect between the most popular allergy medications and their ability to treat the most problematic symptom, researchers are still working to develop new treatments. Ves Dimov, MD (@Allergy), an allergist/immunologist in the Section of Allergy, Asthma and Immunology at the University of Chicago Medicine, recently wrote a review of new treatments for allergic rhinitis with resident Jamee Castillo, MD. The review, published in the journal Expert Opinion on Investigational Drugs, looked at several new treatments that can ease symptoms more effectively or even cure patients long term.“The problem with the currently available treatments is that some of them are ineffective for nasal congestion, such as oral antihistamines. Others are effective, such as the nose sprays, but patients don’t like them for one reason or another,” Dimov said.
The most promising developments rely on a combination of medications to treat different symptoms, Dimov said. One new nose spray, Dymista, uses a combination of antihistamine and steroid to treat both the inflammation causing nasal congestion and the common sneezing and itching symptoms. Another, Nasacort, is a prescription-strength nasal steroid now available over the counter to treat congestion.
A more recent advance, just approved by the FDA in April, is sublingual immunotherapy, or SLIT. These are tablets that work on a similar principle as the allergy shots that have been in use for more than 100 years. Patients are tested carefully for sensitivity to specific allergens, and then small, gradually increasing doses of a solution containing these allergens are given until their immune system learns to tolerate them.
Allergy shots pose a logistical challenge for patients though. In the beginning they’re given every week—in a doctor’s office—and then once a month for 3 to 5 years. The therapy can be effective up to 5 to 10 years after that, but many patients give up before they finish the course. Tablets can be taken at home, and give patients with less severe symptoms who may not go through the trouble of allergy shots a more accessible option.
The first tablets for grasses and ragweed are available now, and Dimov said he expects more varieties for treating cat and dust mite allergies will be available in the next two to five years.
Other, more advanced treatments are further out. Molecules that target the mechanisms such as toll-receptors causing inflammation in the immune system are 5 to 15 years from clinical use. Intralymphatic immunotherapy, in which injections are given directly into the lymph nodes, is also at least 2 to 5 years away.
Despite these improvements, the new treatments have drawbacks. Oral immunotherapy tablets are expensive right now, $200-300 a month, compared to $20-30 a month for traditional allergy shots. And because the oral immunotherapy tablets are introducing a known allergen to the body, they carry the risk of triggering anaphylaxis, or serious reactions including extremely low blood pressure and rapid swelling in the throat that can be deadly. Patients taking these medications must have an epinephrine auto-injector, such as an EpiPen, that can cost an additional $300-400 a year.
Dimov said that while none of these options are perfect, in the near future, patients would be able to use a combination of new drugs with conventional over-the-counter therapy for the most effective relief. So while new medications are on the horizon, don’t count on the end of those TV commercials just yet.
“These are promising developments. It is nice to have more options, but they come with strings attached. See a board-certified allergist to find the best approach that works for you”, he said.
Castillo J. & Dimov V. (2014). Investigational drugs for the treatment of allergic rhinitis., Expert opinion on investigational drugs, PMID: 24708183