When she was in fifth grade, Scarlett Goddard Strahan started to worry about getting wrinkles. By the time she turned 10, Scarlett and her friends were spending hours on TikTok and YouTube watching influencers tout products for achieving today's beauty aesthetic: a dewy, "glowy," flawless complexion. Scarlett developed an elaborate skin care routine with facial cleansers, mists, hydrating masks and moisturizers.

One night, Scarlett's skin began to burn intensely and erupted in blisters. Heavy use of adult-strength products had wreaked havoc on her skin. Months later, patches of tiny bumps remain on Scarlett's face, and her cheeks turn red in the sun.

"I didn't want to get wrinkles and look old," says Scarlett, who recently turned 11. "If I had known my life would be so affected by this, I never would have put these things on my face." Scarlett's experience has become common, experts say, as preteen girls around the country throng beauty stores to buy high-end skin care products, a trend captured in viral videos with the hashtag #SephoraKids.

Girls as young as 8 are turning up at dermatologists' offices with rashes, chemical burns and other allergic reactions to products not intended for children's sensitive skin. "When kids use anti-aging skin care, they can actually cause premature aging, destroy the skin barrier and lead to permanent scarring," says Dr. Brooke Jeffy, a Scottsdale, Arizona, dermatologist who has posted her own social media videos rebutting influencers' advic.