For people like Hayes with psoriasis, or for others with the skin allergy eczema, the sensation can be unbearable. "Itching is the worst thing," says Susan Lipworth of Bloomfield Hills, Mich., who has had eczema for 13 years. "It never stops -- it never stops -- it wears you down."
Lipworth, who is also a board member of the National Eczema Assn., a patient advocacy group, says that scratching becomes so automatic, she even does it while sleeping. "I'm waking my husband up with my scratching," she says.
An estimated 4.5 million adult Americans have psoriasis and 9 million have eczema, according to the American Academy of Dermatology, most tolerating long-term itch that doesn't go away with scratching. Burn patients, and people with certain kinds of nerve damage, also often have severe itching -- as can people with liver and kidney diseases and some who are infected with HIV, due to the infection itself and the medicines they must take.
Such itches can erode a person's mental health, experts now say.
Many studies have found that people with severe itching from psoriasis, eczema and kidney dialysis are more likely to be depressed than others. In a 1998 study published in the British Journal of Dermatology, for example, researchers from the University of Western Ontario in Canada reported that almost 10% of 217 patients with psoriasis had had suicidal thoughts.
For many people, the itchiness also prevents them from sleeping. In a study in 2002, Yosipovitch found that 84% of 102 eczema patients had trouble falling asleep due to itching.
Lack of sleep is a particular problem in children with eczema. (The condition affects more children than adults.) A 1995 study, conducted at the Maelor Hospital in Wrexham, United Kingdom, estimated that preschoolers with eczema lost an average of two hours of sleep per night, and that the deficit led to behavioral problems at school.
Rebecca Litke, a professor at Cal State Northridge, has a 12-year-old daughter with eczema. "My daughter, for the first eight years rarely slept through the night," she says. That meant that Litke rarely did, either. "It has been awful," she said. "For years you're functioning on three or four hours a night."
Lack of sleep due to itching can affect people's physical health, Yosipovitch says. "It affects even mortality," he says. Last year, a group of scientists lead by Ronald L. Pisoni at the Arbor Research Collaborative for Health in Ann Arbor, Mich., completed a study of almost 19,000 people over eight years who had itching due to kidney dialysis. They found that moderate to severe itching resulted in a 17% higher chance of dying, mostly linked to lack of sleep.
