Assessment of Skin Physiology Change and Safety After Intradermal Injections With Botulinum Toxin: A Randomized, Double-Blind, Placebo-Controlled, Split-Face Pilot Study in Rosacea Patients With Facial Erythema

BACKGROUND Botulinum toxin (BTX) has been used cosmetically with good clinical efficacy and tolerable safety. OBJECTIVE This randomized, double-blind, split-face clinical study aimed to investigate the efficacy and safety of intradermal BTX in patients with rosacea. MATERIALS AND METHODS Twenty-four participants were enrolled and randomly given intradermal injections of BTX and normal saline in both cheeks. Clinician Erythema Assessment (CEA) score, Global Aesthetic Improvement Scale (GAIS) score, skin hydration, transepidermal water loss (TEWL), melanin content, erythema index, elasticity, and sebum secretions were evaluated at baseline and 2, 4, 8, and 12 weeks. RESULTS On the BTX-treated side, the CEA score significantly decreased and the GAIS score significantly increased. The erythema index decreased at Weeks 4 and 8. Skin elasticity was improved at Weeks 2 and 4 and skin hydration, at Weeks 2, 4, and 8. However, TEWL and sebum secretion did not show significant differences. CONCLUSION Intradermal BTX injections reduced erythema and rejuvenated the skin effectively and safely in patients with rosacea.