Differences of skin irritation between Japanese and European women.
BACKGROUND
After using cosmetics, Japanese women frequently complain about sensitive, stinging skin. We wondered whether Japanese women's skin is more sensitive than that of Caucasians.


OBJECTIVE
To examine possible racial differences of skin irritation and subjective sensations.


METHODS
We performed patch testing on the forearm with sodium lauryl sulphate (SLS) at different concentrations (0.25%, 0.5%) and 24-h exposure time. Skin reaction was evaluated by measurement of transepidermal water loss (TEWL), stratum corneum hydration, sebum secretion, laser Doppler flowmetry (LD), content of melanin and erythema. During a stinging test with 10% lactic acid (applied to one side of the cheeks) the subjects were asked to describe the present intensity of any sensation. We used a Chromameter to measure skin colour before and after application of lactic acid. This study was performed in Marburg, Germany, with healthy Japanese and German women living in Marburg.


RESULTS
After SLS testing, we found no significant differences of the barrier function in the stratum corneum, but we found significant subjective sensory differences between Japanese and German women.


CONCLUSIONS
Japanese women may complain about stronger sensations reflecting a different cultural behaviour rather than measurable differences in skin physiology; however, a faster penetration of SLS in Japanese cannot be excluded.
Aramaki
J
J
Department of Dermatology, Nippon Medical School, Japan.
Kawana
S
S
Effendy
I
I
Happle
R
R
Löffler
H
H
D000328:Adult; D044466:Asian People; D003877:Dermatitis, Contact / Q000208:ethnology*; D005260:Female; D005858:Germany / Q000208:ethnology; D006801:Humans; D007564:Japan / Q000208:ethnology; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D010328:Patch Tests / Q000379:methods; D023422:Skin Irritancy Tests / Q000379:methods; D012967:Sodium Dodecyl Sulfate; D013501:Surface-Active Agents; D044465:White People
D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate