Hay fever sufferers may soon have a new weapon against pollen. Danish researchers have developed a mini “nasal filter” that blocks the inhalation of allergens and reduces sneezing, watery eyes, and other symptoms by half or more.

Clinical studies of the new filter, carried out by Aarhus University, found the device to be well-tolerated by 65 people with grass pollen allergies — potentially offering a new drug-free way to combat hay fever.

"The nasal filter more than halved a number of the most common symptoms such as sneezing, runny nose and watery eyes,” said lead researcher Torben Sigsgaard, a professor at Aarhus University.
“And when participants initiated use of the filters before symptom onset, the effects were even more pronounced, which we see as an indication of the nasal filter's preventive effect."

About 500 million people worldwide suffer from seasonal allergic rhinitis. Most take allergy medications to ease their symptoms, but they can carry significant side effects, including drowsiness.

Tests of the nasal filter showed participants’ sneezing and watery eyes were reduced by 100 percent, runny noses were decreased by 84 percent, and drowsiness dropped by more than 50 percent.

"This is interesting because drowsiness is a well-known side-effect of some of the most frequently used antihistamines, and for some, having allergy can in itself result in tiredness. So for some allergy sufferers, this could perhaps turn out to be the most important benefit of the filter," said Sigsgaard.

The study was presented at the 2015 annual Congress of the European Academy of Allergy and Clinical Immunology in Barcelona is slated for publication in the Journal of Allergy and Clinical Immunology.