INTRODUCTION
Fractional carbon dioxide (CO₂) laser skin resurfacing is widely recognized as the gold standard for skin rejuvenation. Its effectiveness is based on the principle of selective photothermolysis, wherein the CO₂ laser's 10,600-nm wavelength is highly absorbed by water, resulting in controlled vaporization and ablation of epidermal and dermal tissues.1,2 This precise thermal injury initiates a series of biological responses, including neocollagenesis and extracellular matrix (ECM) remodeling.1,3,4 Although serious adverse events are rare, fractional CO2 resurfacing can cause prolonged erythema or delayed healing, limiting recovery and patient satisfaction.4,5 Appropriate postprocedural skin care is therefore essential to promote rapid healing, optimize treatment outcomes, and minimize side effects and discomfort (ie, itch) during recovery.6
Carboxytherapy is a therapeutic technique that uses CO2 to promote tissue repair and regeneration. First described in the 1930s, its origins trace back to observations that bathing in naturally carbonated waters accelerated the healing of ischemic ulcers.7 It was later adapted into subcutaneous CO2 injection. Mechanistically, CO2 increases local tissue tension, inducing vasodilation and capillary recruitment that enhance tissue perfusion, oxygen delivery, and clearance of metabolic byproducts. Increased tissue-level CO2 also lowers extracellular pH, shifting the oxyhemoglobin dissociation curve and facilitating oxygen (O2) release from hemoglobin (Hb).8 Improved tissue perfusion and transient hypoxia-like signaling activate fibroblasts, upregulating growth factors such as vascular endothelial growth factor (VEGF) and promoting collagen and elastin synthesis.9-11 These mechanisms form the basis for carboxytherapy in dermatologic applications, including photoaging, scarring,12 localized fat deposits,13 dark infraorbital circles,14 alopecia,15 and postprocedural recovery,16 as well as experimental use in inflammatory and pigmentary conditions such as psoriasis17 and vitiligo,18 respectively.
Carboxytherapy is a therapeutic technique that uses CO2 to promote tissue repair and regeneration. First described in the 1930s, its origins trace back to observations that bathing in naturally carbonated waters accelerated the healing of ischemic ulcers.7 It was later adapted into subcutaneous CO2 injection. Mechanistically, CO2 increases local tissue tension, inducing vasodilation and capillary recruitment that enhance tissue perfusion, oxygen delivery, and clearance of metabolic byproducts. Increased tissue-level CO2 also lowers extracellular pH, shifting the oxyhemoglobin dissociation curve and facilitating oxygen (O2) release from hemoglobin (Hb).8 Improved tissue perfusion and transient hypoxia-like signaling activate fibroblasts, upregulating growth factors such as vascular endothelial growth factor (VEGF) and promoting collagen and elastin synthesis.9-11 These mechanisms form the basis for carboxytherapy in dermatologic applications, including photoaging, scarring,12 localized fat deposits,13 dark infraorbital circles,14 alopecia,15 and postprocedural recovery,16 as well as experimental use in inflammatory and pigmentary conditions such as psoriasis17 and vitiligo,18 respectively.
