Stander's itch clinic has been successfully treating some patients with another drug called aprepitant (Emend) that blocks substance P directly. And sometimes, she says, low doses of antidepressants such as paroxetine (Paxil) or mirtazapine (Remeron) can help.
No one knows quite why, but two pilot studies in the last five years have found that mirtazapine can relieve some people's itching, particularly at night -- even in people who aren't depressed.
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Getting to the source
Treating the itch itself is good, but it would be better to keep the itch-scratch cycle from spiraling out of control in the first place.
People with eczema, for example, sprout extra nerve endings where their skin is inflamed, making them more and more sensitive to itch as the years go by. A substance called nerve growth factor drives the nerves to sprout. It may be one key to stopping the runaway itching.
In a study published in February in the British Journal of Dermatology, scientists at Taisho Pharmaceutical Co. in Saitama, Japan, found that blocking nerve growth factor's activity with drugs called AG879 and K252a reduced the amount that mice with eczema scratched themselves. Not only did the eczema not get worse, it actually decreased in severity over the duration of the study.
Human trials of AG879 or K252a aren't planned yet, but Schmelz is hopeful that they will ultimately be helpful for itchy humans, not just mice.
As scientists continue to probe the complexities of itch and pain sensation, people with chronic itchiness keep a weather eye on the developments. Right now, say itch experts, doctors have no agent as good at treating itch as aspirin is at treating pain. Patients must do what they can to keep on going.
Cordio, whose psoriasis was diagnosed in 1998, has finally managed to clear up most of her skin. She had rough periods in the past: "I've been as much as 90% covered. Let me tell you, that's not a fun way to be."
She's tried a variety of different medications, none of which were particularly effective. Recently, she's started a new drug -- efalizumab (Raptiva), which interferes with the immune cells responsible for skin inflammation. "This was my lucky ticket," she says. "This is the first time in all the years that I've had psoriasis that I've had this significant a clearing."
There's always a worry that her skin will flare up again. "I have a tendency to live in a cautious joy," she says, "but I never know when [the itch] is going to come back."
For now, though, "It's a kind of freedom. There's a freedom from the flare; there's freedom from that constant burden of scratching.
"It is liberating," she says, "when the itch is not there."
