A Deadly Hospital Fungus Hides in Hair Follicles

A patient recovering in a hospital bed has no way of knowing if Candida auris is living on their skin. No rash. No itch. Nothing to feel or see. The danger starts only if a wound or IV line gives the fungus a route past the skin into deeper tissue.

It kills about 3,000 patients in hospitals and long-term care facilities a year in the U.S. And once it takes hold, there's no reliable way to clear C. auris from the skin. A UCSF study published in Science finally explains why, and the mechanism is stranger than anyone expected.

To understand what lets C. auris persist on the skin when other fungi can't, researchers compared it with Candida albicans, a common skin fungus the immune system normally clears within days. In mice, C. albicans disappeared quickly. C. auris didn't; it took refuge in hair follicles.

The reason it stays isn't passive. The fungus reshapes its own cell wall to expose more of a substance called chitin, prompting nearby immune cells to release interferon gamma, a signal more commonly associated with antiviral defenses. That signal turns against the skin: it suppresses IL-17, blunts the skin's antifungal response and slows how quickly follicle cells shed and replace themselves. Worn-out cells linger instead of cycling out, creating exactly the stagnant environment C. auris needs to settle in.

Co-senior author Suzanne Noble says the skin regularly encounters chitin in nature, but the researchers didn't expect to find C. auris deploying its own chitin so deliberately, turning the follicle into a ready-made hiding spot.

The interferon gamma alarm went off exactly as designed. C. auris was just the one holding the trigger.

Read the full story at Discover Magazine, August 2026

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