The rash, which has spread from the crook of my elbow to the base of my wrist, is starting to sprout puffy, crimson welts. It's been three minutes since I rubbed a mound of coarse blond fibers onto my forearm, and what began as a mild prickling sensation has escalated into a throbbing itch. Diana Bautista doesn't seem concerned. "Will scratching make it worse?" I ask. She nods. "Yes, but it will feel really good while you're doing it."
This unsanctioned self-experiment is taking place in the kitchenette of Bautista's University of California, Berkeley, lab. The source of my discomfort is itch powder, the kind anyone can pick up at a novelty store. Its blue packet shows a cartoon man writhing in agony. Below him, in bold letters, are the words, SURPRISE THAT SPECIAL FRIEND! "It's kind of weird people can just buy this stuff on Amazon and not know what it is," Bautista says. A professor of cell and developmental biology, she's pretty sure she knows what the ingredients are: rose-hip hairs and fiberglass. Itchy stuff for sure, but there are far more distressing things in her lab.
Bautista is one of a small but growing number of researchers in the United States trying to decode the molecular secrets of itchiness. She arrived at the specialty the way many others in her field have: by studying pain. For most of medical history, itch and pain were considered variants of the same sensation — itch being just a mild form of pain. What Bautista and others have shown is that while the two share many cellular receptors and molecules, itch has its own biological infrastructure. It's these largely unmapped internal pathways that Bautista has been working to identify for the past seven years.