Nasal filter new weapon against hay fever

Apr 5 2005

The first clinical trial of a nasal filter has shown that they can significantly reduce both the number of people experiencing symptoms and the severity of their symptoms.

Published in the latest edition of Allergy the research paper shows that on average people using the filter recorded a 68% reduction in the severity of symptoms when compared with people wearing a placebo filter.

Dr Tim O'Meara, Allergy Group, Woolcock Institute of Medical Research, said 'After spending 1 hour outdoors with high levels of pollen, including 20 minutes sitting beside a large patch of ragweed, only 15% of people wearing the filter reported any increase in symptoms compared with 63% of people not wearing the filter'.

The soft plastic filter tubes sit inside the nasal cavities and were shown to capture 98% of inhaled pollens. Participants in the trial noted decreases in symptoms such as sniffles, sneezes, runny nose, itchy throat, nose and eyes, and watery eyes.

For many of these symptoms participants wearing the filter recorded the severity of their symptoms to be lower while wearing the filter than prior to commencing the trail, suggesting that the filter both prevented development of symptoms and also allowed any pre-existing symptoms to resolve.

Dr Tim O'Meara said, 'The level of improvement in symptoms seen in people wearing the nasal filter was beyond what is usually seen for common medications, such as anti-histamines when tested under similar condition.'

Nasal allergies affect between 20 and 40 percent of the population. The majority of people currently use pharmaceutical products to treat symptoms, however, 74 per cent report that the medications do not adequately control symptoms and 65 per cent don't like taking medication because of the side-effects.

Dr O'Meara added, 'The filters are easy to breathe through, and work by capturing particles such as pollens as they are inhaled, but before they can cause an allergic reaction'.

In the trail 46 people known to be allergic to ragweed or grass pollen wore either real or placebo filters. The people spent two hours outdoors in a park where ragweed and grass pollen levels were high. Their allergy symptoms were measured every 30 minutes.

Over 90% of participants in the study indicated they would be willing to wear the nasal filter again.

The filter device was initially developed five years ago by the Woolcock Institute with a view to finding out what was in the air people were breathing that caused hay fever symptoms.