A new review article was published in February 2010, entitled "Is Asian Skin Really Different from Black or Caucasian Skin?". Wiechers not only poses this question, but also answers it. He suspects that the enhanced sensitivity of Asian skin is caused by the route of penetration, namely via pores. Asians, in particular East-Asians, have bigger pores which causes an enhanced influx of chemicals like lactic acid, leading to enhanced skin sensitivity in these people.
Those with access to the digital edition to the Cosmetics & Toiletries Magazine can download it here [1] (until March, 2010).
Cosmetics & Toiletries, vol. 125, no 2. pp. 66 - 73.
Links:
[1] http://cosmeticsandtoiletries.texterity.com/cosmeticsandtoiletries/201002?sub_id=BzplBE2ropatz&folio=66#pg68