Statistical Observation of Sensitive Skin and Evaluation of Subjective Irritation Using Lactic Acid Sting Test / 대한피부과학회지

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 widely accepted as a marker of skin sensitivity and employed for the selection of subjects experiencing invisible sensory irritation. OBJECTIVE: To carry out an epidemiological study to assess the prevalence and possible related factors of sensitive skin in a regional population, and to examine the relationship between sensitive skin and subjective irritation using the lactic acid sting test. METHODS: A total of 514 people responded to self-assessment questionnaires composed of questions about the self-perception, related factors, symptoms and signs of sensitive skin. We assessed subjective irritation using the lactic acid sting test in 54 volunteers. RESULTS: The results are summarized as follows: 1. The incidences of self-reported sensitive skin were 55.7% for women, 38.9% for men and 51.0% for all responders. 2. The family history and seasonal variation of sensitive skin were significantly more common in sensitive skin group. 3. The face especially the cheek area was the most sensitive portion of body, cosmetics were common irritants. 4. The lactic acid stinging scores were significantly higher in the sensitive skin group. CONCLUSION: Our survey indicated that sensitive skin is a common problem for people and a complex problem with genetic, individual, environmental implications and the lactic acid sting test is a valuable method to define skin sensitivity.

Evaluation of Subjective Irritation Using the Lactic Acid Sting Test in Atopic Dermatitis / 대한피부과학회지

BACKGROUND: Subjective or sensory irritation is defined as the experience of various neurosensory discomforts such as stinging, burning and an itching sensation after using certain cosmetics and skin care products. It is unaccompanied by signs of inflammation, such as erythema, scales and edema. Subjective irritation was commonly seen in atopic dermatitis. But few studies pointed out this subject yet. OBJECTIVE: The purpose of this study was to evaluate the subjective irritation in atopic dermatitis. METHODS: In 40 fealty volunteers, (20 atopic dermatitis patients and 20 controls), we assessed subjective irritation using the lactic acid sting test. We divided the subjects into what we called stingers and non-stingers by the lactic acid sting test. To compare the two groups and to determine correlations with the lactic acid sting test, medical histories regarding stinging, DMSO testing and SLS irritation testing were undertaken. RESULTS: The results are summarized as follows: 1. A history of previous subjective sensation was significantly more common in stingers than in non-stingers (p<0.05). 2. The lactic acid stinging score and the history of subjective sensation were higher in the atopy group than in the control group. 3. There was no difference between the atopy group and the control group in the DMSO test results. There was no correlation between the results of the lactic acid sting test and the DMSO test. 4. Baseline TEWL was higher in the atopy group than in the control group. There was no difference in the (delta)TEWL between the two groups. 5. There was a high correlation between the lactic acid stinging score and the baseline TEWL in the control group (p<0.05). However in the atopy group, there was no such correlation. CONCLUSION: A history of previous subjective sensation and stinging were more common in the atopy group than in the control group. There was a high correlation between the lactic acid stinging score and baseline TEWL in the control group, but in the atopy group there was no such correlation. There seem to be other important factors leading to the development of subjective irritation in the atopy group, such as higher density of the cutaneous nerve fibers.