A method of using a diffusion-based, continuous-monitoring system to analyze the effect of an allergen on skin includes creating and maintaining a diffusion channel in an area of skin. The skin is contacted with an allergen. Information related to at least one antibody, histamine and/or leukotriene is continuously monitored for a desired duration via a diffusion-based, continuous-monitoring device. Information related to the at least one antibody, histamine and/or leukotriene is analyzed to determine the effect of the allergen on the skin.