Comparative split-face study of durational changes in hyaluronic acid fillers for mid-face volume augmentation.

Subsequent changes after injection should be considered when determining the precise volume of injected dermal filler. Several studies have used scoring systems to evaluate facial volumes; however, these scoring systems are not particularly objective. This present study aimed to evaluate the volumetric changes over time on three-dimensional (3D) images and the maintenance potential of various hyaluronic acid (HA) fillers used for mid-face volume augmentation. This split-face clinical study included nine Korean subjects who each received a mid-facial injection of the test filler (B) on one side and a random control filler (J, R, or Y) on the contralateral side. Global, photographic, and 3D scanning assessments were conducted at baseline and after 30 min, 3 days, and 2, 4, 12, and 24 weeks. In all nine cases, the 3D images revealed the largest differences in height where the test filler (B) was injected. The results of subjective scoring systems correlated with the results of 3D imaging. The volumes of monophasic fillers (B and J) were maintained for longer periods of time than those of biphasic fillers (R and Y). The B filler yielded excellent volumizing and spreading effects and good injectability. This filler would be suitable for injection into high-pressure areas, such as the lateral cheek, chin, and nasolabial fold. Moreover, the 3D imaging analysis provided objective and digitized data. The present authors hope that their data will allow physicians to better understand the durational changes in HA fillers and, thus, provide accurate predictions to their patients.

Multicenter study of preservative sensitivity in patients with suspected cosmetic contact dermatitis in Korea.

As many new cosmetic products are introduced into the market, attention must be given to contact dermatitis, which is commonly caused by cosmetics. We investigate the prevalence of preservative allergy in 584 patients with suspected cosmetic contact dermatitis at 11 different hospitals. From January 2010 to March 2011, 584 patients at 11 hospital dermatology departments presented with cosmetic contact dermatitis symptoms. These patients were patch-tested for preservative allergens. An irritancy patch test performed on 30 control subjects using allergens of various concentrations showed high irritancy rates. Preservative hypersensitivity was detected in 41.1% of patients. Allergens with the highest positive test rates were benzalkonium chloride (12.1%), thimerosal (9.9%) and methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) (5.5%). Benzalkonium chloride and chlorphenesin had the highest irritancy rate based on an irritancy patch test performed using various concentrations. Seven of 30 normal subjects had a positive irritant patch reading with 0.1% benzalkonium chloride and eight of 30 normal subjects had a positive irritant patch reading at 4 days with 0.5% chlorphenesin in petrolatum. Although benzalkonium chloride was highly positive for skin reactions in our study, most reactions were probably irritation. MCI/MI and thimerosal showed highly positive allergy reactions in our study. The optimum concentration of chlorphenesin to avoid skin reactions is less than 0.5%.