If you’ve got seasonal allergies, come spring (and sometimes all the way through fall), you sneeze, you itch, your nose runs and feels as though it’s stuffed with marbles. You’ve probably tried almost every over-the-counter remedy out there and maybe some prescription drugs to get relief: nasal sprays, allergy pills, injections and even saline solutions you pour into your nose from a little pot.

Now there’s another attempt to bring you relief: a tiny filter, the size of a contact lens, that you stick into your nose. The filters typically adapt to the shape of your nose and come in a few sizes to fit your nostril.

The idea is to keep pollen, ragweed and other allergens from entering your nose and setting off symptoms. If the allergens are too fast for you and you’re already feeling the urge to sneeze, the filters still may help reduce your symptoms.

Early studies of one of the products — Rhinix, made in Denmark — reported that users found the filters convenient and comfortable and that the filter reduced symptoms more than a placebo did. But the devices are still new in the United States. Other brands include WoodyKnows, with a design similar to Rhinix, and First Defense, an oval, gauzelike screen with an adhesive ring that fits outside each nostril.

The devices are sold online, but Peter Kenney, founder of Rhinix, said that he is in discussions with potential partners to sell his product more widely in the United States.

The filters are marketed as an alternative to drugs that are ineffective or have bothersome side effects. Some doctors say there’s no harm in trying them, and others say they don’t yet know enough about them.

“As a specialty we don’t yet have the clinical experience to discuss patient benefit intelligently,” said James Denneny, chief executive of the American Academy of Otolaryngology, Head and Neck Surgery.

Stephen Wall, a Washington otolaryngologist, says he would give them out to his patients to try, believing they are safe and can help with nasal symptoms. He’s not sure, however, that many consumers are ready for them.

“I think nasal filters will be a hard sell for most patients as most aren’t keen on wearing things in their nose,” he said. “I start with water irrigation [inserting a liquid-filled dispenser in the nostrils to flush allergens] and have a hard time getting people to comply with that.”

Rhinix includes a flexible frame with a filtering membrane for each nostril. It has a small plastic band that connects the two filters and keeps them in place. The band, though fairly inconspicuous, may put some users off.

“If you are by yourself in a car with pollen blowing in through the vent, you might use it then,” Wall says.

“You would have to be very close to see” the band between the nostrils, says Joshua Rosenthal, an otolaryngologist in Huntington, N.Y. “It’s small and clear, so it blends in with skin.”

Those with especially severe nasal symptoms may be more open to the idea, Wall says.

“It’s a question of whether it would be comfortable. If the pollen is bad enough, they may try anything,” he says, pointing out that people will wear masks on days where pollution levels are high.

Nasal filters not only are less cumbersome than masks but also may be more effective, says Neena Bhatti, an allergist and immunologist in Upper Marlboro.

“I think they would filter out bigger particles so patients inhale less of them, which is how masks work,” Bhatti says. “But while the mask filters some particles, it lets smaller ones in.”

When ragweed, pollen and other allergens enter the nose, they stay there for hours and trigger rhinitis, inflamed mucous membranes of the nose, leading to symptoms including sneezing and a runny or itchy nose. But the reaction may not stop there because the nose and lungs share the same airway.

“So once particles enter the nose, they can trigger not only allergic rhinitis, but the particles can travel into the lungs and cause allergic asthma,” Bhatti says.

Alan Vinitsky, an internal medicine physician in Gaithersburg, sees a lot of patients with multiple chemical sensitivities, including allergies to pollen and other outdoor exposures. He did not think he would recommend nasal filters to his patients because putting something foreign in the nose of a person with many chemical sensitivities could irritate the tissue.

Rosenthal has tried filters himself and recommended them to his patients. “The filter may eliminate symptoms for some and may allow others who require medications to use less of them,” he says.

But don’t expect to find ways to completely avoid all allergens. That’s not possible, he says, “unless you live in a bubble.”