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%.

Intraocular pressure lowering, change of antiapoptotic molecule expression, and neuroretinal changes by dorzolamide 2%/timolol 0.5% combination in a chronic ocular hypertension rat model.

The aim of this study was to examine intraocular pressure lowering, change of antiapoptotic molecules expression, and neuroretinal changes by a commercially available dorzolamide 2%/timolol 0.5% combination in a chronic ocular hypertension rat model. Chronic ocular hypertension was induced by three episcleral vein cauterizations. The expression of antiapoptotic molecules and the effect of dorzolamide 2%/timolol 0.5% combination in chronic ocular hypertensive retina were evaluated. Retinal ganglion cell (RGC) retrograde labeling and quantification with 4-di-10-ASP (DiA) and expression of glial fibrillary acidic protein (GFAP) were detected before and after the administration of dorzolamide 2%/timolol 0.5%. Treatment of ocular hypertensive eyes with dorzolamide 2%/timolol 0.5% significantly reduced, intraocular pressure when compared to the control eyes. Labeling of RGCs with DiA showed a significant decrease in RGC loss after the administration of dorzolamide 2%/timolol 0.5%. GFAP expression revealed a significant decrease in retinal damage after dorzolamide 2%/timolol 0.5% administration. However, dorzolamide 2%/timolol 0.5% did not affect Bcl-2 and Bcl-xL mRNA expression. In conclusion, dorzolamide 2%/timolol 0.5% may have neuroprotective potential in the animal model, which is not mediated by Bcl-2 or Bcl-xL. The mechanism of neuroprotection by dorzolamide 2%/timolol 0.5% in chronic glaucoma models requires further investigation.