Comparison of Results of Lactic Acid Sting Tests between Sensitive Skin and Nonsensitive Skin after Tape Stripping

Lee, Weon Ju; Jang, Yun Hwan; Kim, Do Won; Lee, Seok Jong; Na, Gun Yeon; Chung, Sang Lip

Abstract

BACKGROUND
Sensitive skin has been described as a skin type showing higher reactivity than normal skin and developing exaggerated reactions when exposed to internal stimulants and external irritants. The Lactic acid sting test is a widely accepted method for evaluating sensitive skin and is employed for the selection of subjects experiencing invisible sensory irritation. Tape stripping of skin is a useful method for removing stratum corneum which plays a most important part in the barrier function of the skin. Measurement of the transepidermal water loss (TEWL) is the standard method to determine stratum corneum barrier status. A disturbed skin barrier is characterized by high TEWL. OBJECTIVE: The author performed this study to compare lactic acid sting test between sensitive skin and nonsensitive skin after tape stripping, not on the face but on the forearm. METHODS: A total of 40 individuals (20 individuals of the sensitive skin group and 20 individuals of the nonsensitive skin group) were selected by the method of self-assessment questionnaires related to sensitive skin. The individuals were tested a total of 6times, at internals of 2weeks, on the volar aspects of both forearms with 10% lactic acid after tape stripping, with or without a Hilltop chamber. The frequency of tape stripping was divided according to the TEWL into 3 groups as follows: mild(increase of TEWL> or = 5g/m2h compared to baseline TEWL), moderate (> or = 10g/m2h), and severe (> or = 20g/m2h). RESULTS: When 10% lactic acid sting tests were performed after mild and moderate tape stripping of skin, irrespective of the Hilltop chamber, there were more positive responders in the sensitive skin group (p<0.05). Also statistically, there was a significant difference between the sensitive skin group and the nonsensitive skin group in the comparison of the mean values of lactic acid sting scores (p<0.05). However, when 10% lactic acid sting tests were conducted after severe tape stripping of skin, irrespective of the Hilltop chamber, there were no statistically significant difference between two groups when comparison of the positive rates and the mean values were made. CONCLUSION: The Lactic acid sting test with the Hilltop chamber, after mild and moderate tape stripping is a useful method to discover sensitive skin.