“…It is well known that differences in housing density and environmental conditions can affect the behavior, physiological functions, and immune function of rodents due to psychological stress [1, 3-6, 9, 15, 17, 19]. In humans, the involvement of psychological factors and stress in atopic dermatitis (AD), a representative allergic dermatopathy, is widely recognized [2,14,16]. For these reasons, psychological stress might play a role in the development and aggravation of wet skin lesions in the NOA mouse.…”