Abstract
In vivo imaging is a novel experimental approach for biological research.Multiphoton microscopy (MPM),
a type of fluorescence microscopy, is a new tool for in vivo imaging analysis. MPM allows observation of
both tissue structures and cell behaviors or cell-cell interactions in living animals in real time. Skin is an
ideal tissue for MPM analysis as it is directly accessible to the microscope. In the skin, immune cells
cooperate to maintain skin homeostasis or to exert immune responses against foreign antigens. In vivo
imaging by MPM analysis provides precise information on cell dynamics in the skin, and has significantly
expanded our knowledge of the cutaneous immune system. In this review, we will discuss recent insights
related to the mechanisms of allergic skin inflammation that have been revealed by MPM analysis.
