Alternative nonvisual methods quantitating skin test response

Several noninvasive techniques based on different physical principles have been developed to investigate skin function and have been used for skin test responses. Measurements of skin blood flow and erythema, skin thickness, and TEWL may provide a useful tool in assessing skin reactions. In this article, the advantages and the defects of these methods are described in light of the more recent data available in the literature. Bioengineering techniques may provide efficient recording systems for monitoring skin color, skin blood flow, and barrier function damage useful to the investigator rather than to the clinician.