Self-perceived sensory responses to soap and synthetic detergent bars correlate with clinical signs of irritation.

Abstract

Epidemiologic studies indicate that after using soaps and other personal care products, many consumers experience irritation. In 50% of the cases the feelings of skin dryness, itching, and stinging occur in the absence of visible signs of irritation. We sought to determine the relation between self-perceived sensory responses of panelists to cleansing products and clinical signs of irritation. A combination of exaggerated arm-washing methods was designed to induce clinical signs of irritation with psychometric techniques developed to quantify sensations. Two studies demonstrated that panelists could reproducibly differentiate between products on the basis of the sensations they felt and that there was a significant correlation (frequently r > 0.80) between these and the observable signs. In the case of skin dryness panelists differentiated products several washing cycles before observable differences were detected. Sensory evaluations of irritation yield additional information on soap and detergent irritancy beyond clinical observations and expand understanding of the irritation process.