!What Are Mast Cells and Why Do They Matter for Sensitive Skin? - SUSHENAH scientific illustration Mast cells are immune cells in your dermis that release histamine and other inflammatory mediators when triggered—and they explain why sensitive skin reacts to so many things. According to research in Andrews' Diseases of the Skin, mast cell mediators "may be pivotal to the genesis of an inflammatory response." Here's what that means for chronic sensitivity. When mast cells detect a trigger—allergens, temperature changes, certain ingredients—they release their contents. Histamine dilates blood vessels. Other mediators signal irritation. Redness, swelling, itching. The classic sensitivity response. But research also shows mast cells "may be capable of regulating inflammation, host defense, and innate immunity." They're not malfunctioning. They're protecting. The question isn't how to eliminate the response. It's identifying what's triggering it. Understanding inflammation means looking at the source—not just calming symptoms.
