Editor's note: Lauren Hart was first profiled in The State News on Nov. 15, 2006.

The last several months have brought ups and downs for Lauren Hart.

The 11-year-old, who was diagnosed with a rare disease called Pythiosis last July, spent most of March at her home in Millington, Tenn.

Lauren was waiting for a chance to try out her new swimming pool, and she saw a tutor twice a week to learn math, her favorite subject.

"When she went home, she was much better," said Sandra Arnold, assistant professor of pediatrics in the infectious diseases division at the University of Tennessee Health Science Center.

Lauren has been in and out of a children's hospital in Memphis since her diagnosis. On Friday, Lauren returned to the hospital because her swelling had returned.

"We had to treat her with steroid medication because she had gotten so swollen," Arnold said.

Pythiosis is caused by the deadly pathogen Pythium insidiosum. The disease inflames the body's tissues, causing ulcers or skin loss and even death if left untreated.

"Nobody knows much about this disease," said MSU biomedical laboratory diagnostics Associate Professor Leonel Mendoza, who is one of the leading experts on the pathogen.

Mendoza created an alternative treatment to surgery known as immunotherapy. He has worked with Lauren's doctors in Tennessee to treat her and continues to keep in contact with Arnold through e-mail.

Pythium insidiosum is found naturally in the environment, usually in soil and wet places, but few people get sick from it.

Only five people in the United States have been diagnosed with Pythiosis in the last century, which makes it a puzzling disease — one doctors aren't exactly sure how to treat.

Arnold said she thinks there's no live Pythium left in Lauren's body. In late December, she looked at a biopsy of Lauren's scalp.

"We couldn't find anything when we looked under the microscope," Arnold said.

But doctors still are trying to figure out what is in Lauren's tissues that could cause inflammation. The newest bout of swelling came last week when Arnold tried lowering Lauren's steroid dosage.

Now that Lauren has taken steroids for the last two months and the disease seems to be under control, Arnold said she is concerned when the sixth-grader will start eating and breathing on her own.

Lauren had a tracheostomy to help her breathe in late December and has used a feeding tube ever since.

"She hasn't been able to eat," said Lauren's mother, Karen Yarbrough.

Lauren still can't see out of her left eye, where the Pythiosis started, and it's possible she will need a prosthetic eye or plastic surgery on the left side of her face, Arnold said.

"We've got a very long haul ahead of us, waiting to see what happens," Arnold said.

But Lauren is resilient, both her mother and doctor say.

"She's tough," Yarbrough said. "She's done OK."