The relation of warmth and pain thresholds to skin pigmentation.

Thermal sensitivity increases with skin pigmentation. Absolute thresholds for warmth and pricking pain decreased as skin color increased for 13 Caucasian, 3 Mexican, and 4 Negro subjects. These data replicate and extend a previous psychophysical study of pain sensitivity and are compared with spectrophotometric data from excised skin. The results are considered to be potentially significant for the existence of a dermal light sense.