Chaga mushroom (Inonotus obliquus) extract cut redness, swelling, and skin thickening in dermatitis-model mice while sharply lowering oxidative stress markers and inflammatory cytokines. Antioxidant enzymes were significantly restored, showing stronger protection against free-radical damage in inflamed skin. The treatment reduced immune overreaction and helped rebuild the skin barrier, leading to visibly calmer, less damaged tissue.