Mystery of 'Little House' Character's Blindness Solved

little-house-on-prairie — Laura Ingalls Wilder's sister Mary, described in the beloved Little House on the Prairie Books, likely went blind from brain inflammation, not scarlet fever as the books suggest

In Laura Ingalls Wilder's "Little House on the Prairie" books, she describes her sister Mary going blind from scarlet fever. But brain and spinal cord inflammation likely caused Mary's blindness, a new study suggests.

The findings, published today (Feb. 4) in the journal Pediatrics, came from poring over the symptoms Wilder described in memoirs and books.

"Since I was in medical school, I had wondered about whether scarlet fever could cause blindness, because I always remembered Mary's blindness from reading the 'Little House' stories and knew that scarlet fever was once a deadly disease," said study co-author Beth Tarini, a pediatrician at the University of Michigan's C.S. Mott Children's Hospital, in a statement.

Wilder wrote several books describing her life as a pioneer in the mid-1800s. In one, she describes her sister Mary going blind at age 14 in 1879.

At the time, scarlet fever was one of the deadliest scourges for young children. The fever occurs when the bacteria that cause strep throat run rampant in the body, causing a rash, fever, bone and joint pain, and, in serious cases, kidney and liver damage.

To find out what caused Mary's blindness, Tarini and her colleagues investigated local newspapers, the author's memoirs and letters.

They found that Wilder described her sister's disease as a "spinal sickness" and that local newspaper reports said a "hemorrhage of the brain had set in [sic] one side of her face became partially paralyzed."

Those symptoms were more consistent with a disease called meningoencephalitis, an inflammation of the spinal cord and brain, which can result from several viruses.

"Meningoencephalitis could explain Mary's symptoms, including the inflammation of the facial nerve that left the side of her face temporarily paralyzed," Tarini said in a statement. "It could also lead to inflammation of the optic nerve that would result in a slow and progressive loss of sight."

It's not clear why the editors of the book tied Mary's blindness to scarlet fever, but one possibility is that the disease was such a well-known and feared scourge at the time, the researchers suggest.

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Tia is the editor-in-chief (premium) and was formerly managing editor and senior writer for Live Science. Her work has appeared in Scientific American, Wired.com, Science News and other outlets. She holds a master's degree in bioengineering from the University of Washington, a graduate certificate in science writing from UC Santa Cruz and a bachelor's degree in mechanical engineering from the University of Texas at Austin. Tia was part of a team at the Milwaukee Journal Sentinel that published the Empty Cradles series on preterm births, which won multiple awards, including the 2012 Casey Medal for Meritorious Journalism.