Does a Common Bacteria (Staph aureus) Drive Itch?

For years, researchers have looked for the cause of the relentless itch that plagues millions of children with eczema around the world. For the most part, managing itch has revolved around symptom relief. Desperate parents experiment with many imperfect techniques to deal with their child’s vicious urge to scratch. However, the root cause of the urge to itch has been elusive.

Now a new study from Harvard researchers published in the journal Cell suggests that Staphylococcus aureus, a bacteria present on the skin of almost every child with eczema, may in fact be driving their itch. The animal study, in mice, indicated that the bacteria releases an enzyme that stimulates sensory nerves on the skin surface, causing that trademark eczema itch and the urge to scratch.

Researchers were able to identify the specific enzyme (V8 protease) that Staph aureus releases to cause itching. They also pinpointed the specific protein (PAR1) that stimulates the sensory nerves.  By potentially reducing or blocking the enzyme and protein, physicians may be able to alleviate itch in eczema patients in the future. More research is needed to validate the findings in humans, but the study offers hope that these targeted treatments could help manage eczema’s most troublesome symptom.

One of the authors told Harvard News that the reason why staph bacteria has evolved to cause itch may be to spread itself:

“It’s a speculation at this point, but the itch-scratch cycle could benefit the microbes and enable their spread to distant body sites and to uninfected hosts. Why do we itch and scratch? Does it help us or does it help the microbe? That’s something that we could follow up on in the future.”

Receive research updates like this one right to your inbox by subscribing to our newsletter!

Like what we do? Consider donating to GPER!