Pain threshold measurements with cutaneous argon laser, comparing a forced choice and a method of limits

1. With the argon laser technique cutaneous nociceptors can be activated with high specificity and reproducibility making it a useful tool in psychophysical pain studies. This study was designed to examine and compare two different psychophysical methods combined with the argon laser technique. 2. Pain thresholds on different locations of the body and on different skin types were measured with (i) the method of limits and (ii) the forced choice method. 3. A significant correlation between the pain thresholds measured with the two different methods was detected on feet and hands. The method of limits yielded significantly higher pain thresholds in glabrous skin than hairy skin. Higher pain thresholds were also detected on the right side of the body. No statistically significant difference between sexes was found. A high reproducibility over time as well as in-between investigators was found for the method of limits. 4. Its concluded that the argon laser for pain threshold measurement with the method of limits is useful and preferred to the forced choice, since the method of limits is easier to perform and also less time consuming.