(March 3) — Last month, Brooke Owens of Asheville, N.C., began sneezing.

And she continued to sneeze nonstop for three weeks straight.

In what her doctors have dubbed a "medical mystery," Owens' sneezing spell has defied diagnosis time and time again. Doctors have ruled out allergies and neurological disorders.

But even though the cause remains unknown, her family says episodes have come and gone for about two years.

The condition has had profound effects on Owens' day-to-day life. At the height of this most recent bout, her sneezing became so bad that she had to be home-schooled.

Fortunately, for most of us, sneezing is an occasional inconvenience. But for others, like Owens, the impact of uncontrolled, repetitive sneezing can take a dramatic toll on daily activities.

And for many, the possible health impacts are nothing to sneeze at, either.

Hostage to a 'Machine Gun' Sneeze

For most of us, a sneeze is just a sneeze.

However, Dr. Clifford Bassett, an otolaryngology specialist at the Long Island College Hospital of Brooklyn, says there are many different varieties of sneezes, each of which may hint at the possible root causes of the affliction.

The monikers of these subtypes are evocative, to say the least — the "trumpet sneeze," the "big, bad wolf sneeze," the "cartoon sneeze."

In most cases, he says, occasional bouts of sneezing are nothing to worry about. Bassett says any time there is irritation to the nasal mucosa — the tender inner lining of the nasal passages — the body's natural reaction is to sneeze.

"It's a protective reflex," he says. "In general, sneezing is a good thing."

As for Owens, Bassett classifies her condition as a case of what he calls "machine gun" sneezing. As the name implies, this variant involves a staccato series of sneezes, one right after the other.

In most cases, such sneezing is not terribly atypical.

"It's a phenomenon that is not uncommon," he says. "But in this patient's case, it lasted for three weeks, which makes it very unusual and interesting."

Putting the Lid on Sneezing Fits

Bassett says the fact that doctors have not yet determined the reasons behind Owens' condition suggests that new approaches may be needed to evaluate her.

"We really need to think out of the box when treating a patient like this, because the case here is excessive," Bassett says.

But in many cases, the sources of the irritation behind sneezing fits are easily found — and perhaps include a cold or sinus infection, allergies or a foreign object lodged in a ticklish spot in the nasal passages.

Dr. Jordan Josephson, an otolaryngologist at Lenox Hill Hospital in New York City and author of the book "Sinus Relief Now," says that the most likely culprit in Owens' case is the presence of something in her nasal passages that her body is trying to expel.

"Allergy is only one of the causes of sneezing, and Brooke Owens' sneezing can be caused by an irritant or a small or large foreign body," he says, adding that mold or bacteria inhaled into her sinuses could be to blame.

"There are many things that can be causing Brooke to sneeze, and once the problem is discovered there are many things that we can do to help Brooke."

Dr. Navin Mehta, surgical director of the ear, nose and throat department at the New York Eye and Ear Infirmary, says that absent allergies or an infection, the culprit is likely a foreign body or polyp — a small growth inside the nasal passages.

Mehta, in fact, has firsthand experience with another case of machine gun sneezing. He treated an 11-year-old girl with a similar condition.

"It turns out that she had been cleaning her nose with a tissue, and a piece of the tissue got stuck," he says.

He said after the piece of tissue was removed, the patient improved immediately.

However, not all cases are so easily solved, as seen in Owens' case.

"A complete history needs to be taken, and then a full physical examination needs to take place, possibly including endoscopic examination and CT and/or MRI scanning," Josephson says. "Thorough investigation will probably ultimately find the culprit."

Health Risks of Sneezing?

For the vast majority of people, the effects of a sneeze — or even multiple sneezes in a row — pose little risk to health in general.

But for some, sneezes present a more substantial threat. Attempting to stop sneezes can redirect the high-pressure air through the eustachian tubes of the ears, leading to possible infection or eardrum damage.

Other impacts of sneezes, suppressed or not, can have health implications for a few sufferers.

"There are certain issues as far as blood pressure and heart rhythm are concerned," Bassett says.

However, he adds, "In a young person, such as in this case, this is less of an issue."

In all likelihood, Owens will simply continue to suffer this remarkable inconvenience for a time, which will come to an end when doctors find and vanquish the root cause of her nonstop sneezes.

Until then, Mehta says a common remedy for sneezing can be found over-the-counter — Benadryl.

"Generally that takes care of a lot of the irritation," he says.