A small filter the size of a contact lens could possibly make life easier for some of the estimated 500 million people worldwide who suffer from itching, sneezing and a runny nose as soon as the pollen season starts.
A clinical study from Aarhus University concludes that a newly developed Danish mini-filter - Rhinix - appears to be significantly more effective against the discomfort of seasonal hay fever than a filterless placebo.
The study has just been published online in the Journal of Allergy and Clinical Immunology.
Filter blocks pollen
The filter, which is not yet in production, works by being inserted in both nostrils. Depending on the filter's density, it blocks specific particles in the air - including pollen from grass, which is one of the most frequent causes of hay fever (seasonal allergic rhinitis).
"We will test Rhinix on a larger scale in collaboration with the Danish Patient Organisation Asthma-Allergy Denmark later in the year. But the preliminary tests in our allergy chamber show that the filter can both alleviate typical symptoms, and that you will not experience unacceptable discomfort when using it," says Professor Torben Sigsgaard from Aarhus University, one of the people behind the study together with the inventor of the filter, MD- PhD student Peter Sinkjær Kenney.
And even though the test subjects still had mild symptoms after the treatment, regardless of whether they were in the placebo- or active group, the researchers demonstrated what they describe as "clinically relevant reductions in daily nasal symptoms compared to placebo, in particular supported by reductions in sneezing, itching of the nose and runny nose symptoms."
Less discomfort in the throat
One of the crucial points has been to examine whether the test subjects ceased breathing through the nose when the filter was inserted and instead breathed through their mouth.
"This would probably aggravate their symptoms in the throat, because the air particles would be increased there instead," says Peter Sinkjær Kenney.
But he describes how the project showed that, on the contrary, the test subjects' throat irritation was significantly lowered when using the nasal filter, with an average reduction of 75 percent. At the same time, measurements showed that there was no difference in airflow between the placebo filter and the Rhinix filter.