Histamine and Pruritus: From Molecular Mechanisms to Clinical Therapy

Itching is an unpleasant sensory experience that induces the desire to scratch and is clinically divided into histamine-dependent and non-dependent types, with the former being the main clinical type. Its pathogenesis mainly involves mast cell degranulation due to various factors, releasing histamine and causing itching. Histamine, a classical pruritogen, is mainly associated with acute pruritus and is the main endogenous pruritic agent responsible for pruritus in patients with allergic skin diseases after exposure to allergens. In recent years, significant progress has been made in understanding the neurocircuits of histamine-dependent itch from the periphery to the central nervous system. This review focuses on the neurocircuits of histamine-dependent itch, summarizes the major recent advances in this field, and explores the clinical diagnosis and therapy of histamine-dependent pruritus based on basic neuroscience findings. By delving into the mechanisms of histamine in the generation, transmission, and processing of itch sensation, this article provides a better entry point and theoretical basis for the treatment of pruritus, especially histamine-related pruritus, and helps to develop more effective anti-pruritic drugs in the future to improve patients' quality of life.