Intense itching is a common symptom in various autoimmune skin diseases like herpetic pemphigoid, psoriasis, and certain chronic urticaria. While histamine and neuropeptides were initially thought to cause this itching, recent findings suggest that the cytokine interleukin (IL)-31 plays a significant role in driving the itch response. IL-31 production has been observed in activated helper T-cells, particularly Th2 cells, mast cells, macrophages, and dendritic cells.