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

Abstract Background: 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. Objective: We sought to determine the relation between self-perceived sensory responses of panelists to cleansing products and clinical signs of irritation. Methods: A combination of exaggerated arm-washing methods was designed to induce clinical signs of irritation with psychometric techniques developed to quantify sensations. Results: 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. Conclusion: Sensory evaluations of irritation yield additional information on soap and detergent irritancy beyond clinical observations and expand understanding of the irritation process.