Chronic pruritus may arise from different conditions, including dermatological, systemic, neurologic, psychiatric, and psychosomatic diseases, leading to a substantial decrease in the quality of life of affected patients. The neurobiological mechanisms involved in chronic pruritus are not yet fully understood. However, in recent years important achievements have been made in this regard. This article aims to provide an overview of the current understanding of these mechanisms. The complex network of neurons, keratinocytes, inflammatory cells, cytokines, and neurotrophic factors which play a role in the development and maintenance of chronic pruritus are highlighted, as well as the pruritogens involved in pruritic diseases in humans. Additionally, the importance of neuropathy and scratch-induced changes for the pathophysiology of chronic pruritus are discussed. The new findings on the neurobiological mechanisms underlying chronic pruritus have already led to the development of novel therapies, e. g., monoclonal antibodies against specific interleukins, which are important for pruritus transmission. A deeper understanding of the neurobiological mechanisms is necessary in order to develop specifically targeted therapeutic options and thus provide better care for affected patients.
Keywords: Keratinocytes; Mediators; Neuropathy; Pruritogens; Scratching.