Mouse Study Hints at Treatment for Itch-Related Ills Like Eczema

Rodents with a certain gene had runaway itch, but those without it did not, scientists say

By Robert Preidt

Thursday, June 11, 2015

THURSDAY, June 11, 2015 (HealthDay News) -- An itch that just won't go away: Many people will suffer from eczema or some other ailment involving chronic itch during their lifetime, and a new study in mice hints at why this happens.

The scientists who've spotted a gene involved in chronic itch also believe the finding could lead to new treatments.

The study was co-authored by Rachel Brem, a geneticist and associate professor at the Buck Institute for Research on Aging in Novato, Calif.

"An estimated 10 to 20 percent of the population will suffer from chronic itch at some point in their lifetime," Brem said in an institute news release.

"In addition to eczema, chronic itch can stem from systemic conditions including kidney failure, cirrhosis and some cancers," she added. "Understanding the molecular basis of chronic itch is of significant clinical interest, and now there is a new target available to explore."

Working with mice, the researchers pinpointed a nerve cell receptor called HTR7 as a major player in eczema and other types of chronic itch.

Mice created to have high levels of HTR7 in skin neurons had the worst itching, while those without the HTR7 gene scratched significantly less and had less severe skin problems.

While experts caution that studies in animals often fail to translate to humans, the researchers believe that HTR7 could be a new drug target for chronic itch.

Symptoms of eczema -- which affects up to 10 percent of people worldwide -- include intense itch, rash and dry, flaky skin. There is no cure for eczema, and current treatments to manage the condition are often ineffective.

Dr. Michele Green, a dermatologist at Lenox Hill Hospital in New York City, explains, "The problem with eczema is that the skin begins to itch and gets more irritated as the scratch-itch cycle is not alleviated.

"Currently, there are only topical emollients and antihistamines to help alleviate the symptoms of the rash, itching and burning of the skin," she said.

But another expert said the new study offers patients new hope.

"This is a major breakthrough in our understanding of a common, yet, unsatisfactorily treated symptom associated with numerous dermatologic disorders," said Dr. Andrew Alexis, chair of dermatology at Mount Sinai St. Luke's and Mount Sinai Roosevelt in New York City.

He believes the new findings "set the stage for investigating a new therapeutic target for [chronic itch], which holds promise for the millions who suffer from eczema and other conditions."

The study was published online June 11 in the journal Neuron.

SOURCES: Michele Green, M.D., dermatologist, Lenox Hill Hospital, New York City; Andrew F. Alexis, M.D., chairman, department of dermatology, Mount Sinai St. Luke's and Mount Sinai Roosevelt, New York City; Buck Institute for Research on Aging, news release, June 11, 2015

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