Scientists at Harvard Medical School have shown for the first time that a common skin bacterium -; Staphylococcus aureus -; can cause itch by acting directly on nerve cells.
The findings, based on research in mice and in human cells, are reported Nov. 22 in Cell. The research adds an important piece to the long-standing puzzle of itch and helps explain why common skin conditions like eczema and atopic dermatitis are often accompanied by persistent itch.
In such conditions, the equilibrium of microorganisms that keep our skin healthy is often thrown off balance, allowing S. aureus to flourish, the researchers said. Up until now, the itch that occurs with eczema and atopic dermatitis was believed to arise from the accompanying inflammation of the skin. But the new findings show that S. aureus single-handedly causes itch by instigating a molecular chain reaction that culminates in the urge to scratch.
We’ve identified an entirely novel mechanism behind itch -; the bacterium Staph aureus, which is found on almost every patient with the chronic condition atopic dermatitis. We show that itch can be caused by the microbe itself.”
Isaac Chiu, senior author, associate professor of immunology in the Blavatnik Institute at HMS
The study experiments showed that S. aureus releases a chemical that activates a protein on the nerve fibers that transmit signals from the skin to the brain. Treating animals with an FDA-approved anti-clotting medicine successfully blocked the activation of the protein to interrupt this key step in