Mast Cells in Chronic Inflammatory Skin Pruritus: A Narrative Review

Itch is an unpleasant sensation and a primary symptom of skin diseases. Chronic itch is often pathological and can be a basis for inflammatory, infectious, neoplastic, and autoimmune skin diseases. Mast cells (MCs) are multifunctional innate immune cells situated at the host-environment interface with a pivotal role in the pathogenesis of pruritus. IgE-mediated and non-IgE-mediated MC activators can participate in different pruritus mechanisms in skin diseases. However, the exact functions of MCs in diverse pruritus conditions have not been addressed in detail. In particular, the role of non-histamine mediators released by MCs has been overlooked in chronic itch. This review aims to explore the role of MCs in chronic pruritus and outline the mechanisms of MC activation in various dermatological itch conditions.