Scientists Identify a Culprit for Chronic Itch

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At a Glance

• An immune substance called oncostatin M was found to sensitize and enhance the activity of itch-sensing neurons.
• A drug that blocks oncostatin M activity reduced scratching in a mouse model of chronic itch, suggesting a treatment strategy for persistent itchy skin conditions.

Chronic itch is a common yet hard-to-treat symptom of many inflammatory skin conditions, such as psoriasis. The urge to constantly scratch can seriously impair a person’s quality of life and lead to permanent skin damage. To find an effective treatment, scientists need to better understand how chronic itch develops.

A short-lived itch—from an insect bite, for example, arises when immune substances released by the body activate itch-sensing nerve fibers in the skin. The signal is relayed to the brain, where it is perceived as the sensation of an itch. But scientists haven’t understood how this process may become chronic.