Katelyn Thornley, 12, has doctors baffled by her condition, which causes her to sneeze 20 times a MINUTE

A schoolgirl has been left in constant pain from a mystery condition which causes her to sneeze 12,000 times a day.

Katelyn Thornley, 12, has been sneezing around 20 times a minute for the past month and has seen six doctors but no one can figure out the cause.

Medics do not believe the sneezing - which has caused the youngster to miss school, is caused by allergies or a virus, CBS News reported.

The fits only stop when Katelyn, from Angleton, Texas, sleeps - which she manages by taking Benadryl and listening to Beatles music.

The incessant sneezing is now starting to take its toll.

Katelyn told CBS: "It just started in little spurts. I just started sneezing. I thought it was like, oh, I'm just allergic to something. 

"But now the sneezing fits are taking a serious toll. I'm constantly in pain with my abdomen, my legs are hurting because I've been weak and I can barely eat."

"Sometimes I wish I could leave my body for a little while so I could watch myself sleep because even in my dreams, I sneeze."

Katelyn and her parents have gone public with her plight in the hope that somebody with knowledge of whatever condition she might be suffering from will come forward and offer help.