ANNALS OF MEDICINE
Its mysterious power may be a clue to a new theory about brains and bodies.
t was still shocking to M. how much a few wrong turns could change your life. She had graduated from Boston College with a degree in
psychology, married at twenty-five, and had two children, a son and a daughter. She and her family settled in a town on Massachusetts’
southern shore. She worked for thirteen years in health care, becoming the director of a residence program for men who’d suffered severe
head injuries. But she and her husband began fighting. There were betrayals. By the time she was thirty-two, her marriage had disintegrated.
In the divorce, she lost possession of their home, and, amid her financial and psychological struggles, she saw that she was losing her
children, too. Within a few years, she was drinking. She began dating someone, and they drank together. After a while, he brought some
drugs home, and she tried them. The drugs got harder. Eventually, they were doing heroin, which turned out to be readily available from a
street dealer a block away from her apartment.
One day, she went to see a doctor because she wasn’t feeling well, and learned that she had contracted H.I.V. from a contaminated
needle. She had to leave her job. She lost visiting rights with her children. And she developed complications from the H.I.V., including
shingles, which caused painful, blistering sores across her scalp and forehead. With treatment, though, her H.I.V. was brought under control.
At thirty-six, she entered rehab, dropped the boyfriend, and kicked the drugs. She had two good, quiet years in which she began rebuilding
her life. Then she got the itch.
It was right after a shingles episode. The blisters and the pain responded, as they usually did, to acyclovir, an antiviral medication. But
this time the area of the scalp that was involved became numb, and the pain was replaced by a constant, relentless itch. She felt it mainly on
the right side of her head. It crawled along her scalp, and no matter how much she scratched it would not go away. “I felt like my inner self,
like my brain itself, was itching,” she says. And it took over her life just as she was starting to get it back.
Her internist didn’t know what to make of the problem. Itching is an extraordinarily common symptom. All kinds of dermatological
conditions can cause it: allergic reactions, bacterial or fungal infections, skin cancer, psoriasis, dandruff, scabies, lice, poison ivy, sun
damage, or just dry skin. Creams and makeup can cause itch, too. But M. used ordinary shampoo and soap, no creams. And when the doctor
examined M.’s scalp she discovered nothing abnormal—no rash, no redness, no scaling, no thickening, no fungus, no parasites. All she saw
was scratch marks.