In the most recent issue of The New Yorker, Dr. Atul Gawande delves into the mystery of itch, that most curious of sensations that rides the boundary between pain and nuisance. Following the story of an anonymous chronic itch sufferer (referred to as “M.”), Gawande explains how bad itch can get — and a word of warning, it gets very bad! Gawande proceeds to examine itch throughout history — a fascinating read. Here’s a taste:

The internist prescribed a medicated cream, but it didn’t help. The urge to scratch was unceasing and irresistible. “I would try to control it during the day, when I was aware of the itch, but it was really hard,” M. said. “At night, it was the worst. I guess I would scratch when I was asleep, because in the morning there would be blood on my pillowcase.” …nothing the internist tried worked, and she began to suspect that the itch had nothing to do with M.’s skin.

… [M's] itching was so torturous, and the area so numb, that her scratching began to go through the skin. At a later office visit, her doctor found a silver-dollar-size patch of scalp where skin had been replaced by scab. M. tried bandaging her head, wearing caps to bed. But her fingernails would always find a way to her flesh, especially while she slept.

One morning, after she was awakened by her bedside alarm, she sat up and, she recalled, “this fluid came down my face, this greenish liquid.” She pressed a square of gauze to her head and went to see her doctor again. M. showed the doctor the fluid on the dressing. The doctor looked closely at the wound. She shined a light on it and in M.’s eyes. Then she walked out of the room and called an ambulance. …

Although M’s story is grim, the article is a very thorough look at the phenomenon of itching, include a brief survey of itch in literature and philosophy, alongside scientific explorations of itching and scratching. Gawande’s writing will certainly have you itching, imagining some stray annoyance on your scalp. Read the rest for a fascinating exploration of a sensation we all experience — but which, for some people, is a terrible ordeal.

See also: NPR’s All Things Considered piece with Gawande.