[Liminal perception threshold of cutaneous distension].

BACKGROUND

Cutaneous sensorial perception is complex and proves to be difficult to quantify. Skin sensitivity to mechanical distension is largely unexplored. We have developed an original method aimed at quantifiying these physiological parameters.

VOLUNTEERS AND METHODS

The study was performed on 24 adult volunteers aged 20 to 50 years. A Cutometer SEM 474 equipped with 2 and 4 mm diameter probes was used to exert a progressive or a steep suction on the cheeks. The intensities of both the suction and the skin deformation observed at the earliest moment the traction was perceived by the volunteers were recorded.

RESULTS

The liminar sensorial detection under progressive suction force was 1.5 times lower when using the 4 mm probe than the 2 mm probe. Suction necessary for liminar sensation was 7 times lower under steep suction than in response to the progressive mode. The skin deformation corresponding to the liminar sensorial perception was almost constant (C=0.5 p. 100) for each subject. By contrast, a large inter individual heterogeneity unrelated to age was present.

COMMENTS

Sensitivity of facial skin to stretching can be explored using a precise suction method. Perception is more related to the rate of traction than to the surface area submitted to suction. Cutaneous deformation, nearly constant for each individual, appears to be the main parameter. Steep and progressive suctions appear to stimulate distinct types of mechanoreceptors. The presently described method can be applied in cosmetology and in functional investigation of various diseases such as diabetes, acromegaly and atopic dermatitis among others.