This clinical observational study investigates the dose-response relationship between laser energy intensity and skin damage/repair by applying different parameter sets of fractional ablative (CO2) and non-ablative (M22) lasers to the inner forearms of approximately 20 healthy Chinese female volunteers (aged 18-60, Fitzpatrick skin types III-V) in a single-center, self-controlled design. Each participant receives both laser types on contralateral arms, with four distinct energy/density combinations per laser applied to separate test areas, and the dynamic skin responses are evaluated at baseline, immediately post-treatment, and at 30 minutes, 1, 2, 3, 4 hours, 7 days, and 10 days thereafter through clinical assessments (edema, erythema, etc.), standardized photography, high-frequency ultrasound (Dermascan), and objective instrumental measurements of skin color (Chromameter CM26dG), melanin/hemoglobin (Mexameter MX18), and barrier function (TEWL via Vapometer). The collected data will be analyzed using descriptive and comparative statistical methods to characterize the acute injury and recovery profiles, aiming to establish a foundational model for future post-procedure cosmetic intervention research.
Female Chinese study participants aged 18 to 60 years (inclusive).
Fitzpatrick skin phototypes III, IV, or V.
Willing to receive non-ablative fractional laser (M22) and ablative fractional laser (CO2) irradiation on the test sites during the study.
No primary or secondary lesions (such as scars, ulcers, vesicles, tattoos) on the test sites.
Study participants with skin diseases or skin allergies in the test area.
Presence of moderate to severe inflammatory skin diseases (e.g., active eczema, acute photosensitive dermatitis, etc.) on the test sites within the past 4 weeks, or those who require treatment with oral or topical corticosteroids or immunosuppressants for skin conditions.
On the day of the visit, the investigator judges the presence of significant diffuse erythema, desquamation, or exudation in the test area that may significantly affect skin color measurement.
The investigator assesses that the participant is currently suffering from a stable or progressively worsening disease.