The evaluation of hyaluronic acid, with and without lidocaine, in the filling of nasolabial folds as measured by ultrastructural changes and pain management.

Pain management is an important objective in procedures involving dermal fillers composed of hyaluronic acid (HA).To compare the 1-year clinical results of filling the nasolabial fold with 2 types of filler: large-gel particle HA and large-gel particle HA plus 0.3% lidocaine (HA+L). We compared the level of pain during treatment and 10 minutes after treatment and assessed the safety and efficacy profile, satisfaction, and histological findings (using reflectance confocal microscopy [RCM]).We performed a comparative, parallel-group, double-blind trial with an external observer (blinded to the type of treatment administered). The filler was applied to the nasolabial fold in 119 patients (HA in 62 patients and HA+L in 57). Patients were followed at months 3, 9, and 12. Pain was evaluated using a visual analog scale. Efficacy and satisfaction were evaluated using the Wrinkle Severity Rating Scale and the Global Aesthetic Improvement Scale. RCM images (n=32) were taken at baseline and at months 3 and 12.Pain: The severity of pain was decreased in patients treated with HA+L on application (P <.001) and 10 minutes later ( P=.008). Efficacy and satisfaction: No significant differences existed between the 2 groups at months 3, 9, and 12. RCM: Skin rejuvenation occurred with a 32% increase in the height of the dermoepidermal junction at month 12 (P <.001), which was similar in both groups. Adverse events: At month 3, the most common adverse events (AEs) were erythema (68%) and hematoma (11%). No AEs were recorded at months 9 or 12.The use of HA+L provides pain relief without affecting efficacy, satisfaction, safety, or the duration of results. RCM showed that the changes in the dermoepidermal junction represented a histological improvement in the skin with similar results in both groups.