Atopic dermatitis (AD) is as chronic, inflammatory skin disorder affecting 20% of the world's population. Intense itch and skin pain are the main symptoms. Research has shown that the proteins interleukins are involved in inflammation and itch in atopic dermatitis. The medicinal product called Lebrikizumab, used for treatment of AD, has shown to block the interleukin called IL-13. The purpose of this experiment is to evaluate the role of IL-13 in itch in both healthy subjects and people with atopic dermatitis.