Social media has become a major channel for the rapid spread of unverified health information. Hyaluronic acid (HA), widely used as a dermal filler under controlled conditions, is also promoted in skincare content online. Improper or unsupervised administration may result in foreign-body reactions and infectious complications, posing a risk especially to adolescents influenced by such trends.

A 16-year-old female presented with acute facial swelling and erythema after self-injecting a commercially available topical serum containing 1% hyaluronic acid into the nasal dorsum using a 21G syringe, imitating a social media video. Examination revealed multiple nasal injection sites with marked edema extending to the eyelids and infraorbital region, while systemic findings and laboratory tests were normal. She was treated with intravenous corticosteroid and antihistamine, followed by oral methylprednisolone, cetirizine, and amoxicillin–clavulanate. During the two-week follow-up, inflammatory findings had regressed without sequelae.

This case emphasizes the dermatological risks of unscientific cosmetic practices promoted on social media. Adolescents represent a particularly vulnerable group, underscoring the need for clinician awareness and preventive education regarding unsafe procedures outside medical supervision.