Please login or create an account. If you do not have access to this content, you will be shown a 30 second preview and licensing options.
- Presentation
The (Patho) Physiology of Itch
Description
The presentation discusses the evolving understanding of itch physiology, highlighting advances in the field over the past decade. Initially overlooked, itch is now recognized as a complex sensory experience regulated by various nerve fibers. The talk details the role of histamine and other mediators in itch perception, including specific pathways through which itch neurons send signals to the brain. Research has identified distinct receptors that mediate itch, such as the Mas-related G protein-coupled receptors (MRGPRs), with implications for potential therapeutic approaches. It's noted that unlike mouse models, which show a more distinct relationship between specific neurons and itch, human neurons exhibit a more polymodal responsiveness, capable of sensing various stimuli beyond itch. The interplay between inflammation and itch is explored, emphasizing the role of neuropeptides and cytokines in itch-related conditions. Advances in treatments like nemolizumab and dupilumab are discussed as significant developments for managing severe itch associated with conditions like atopic dermatitis. The talk concludes with reflections on the dual aspects of itch: as a sensory alarm system for inflammation and its potential to escalate into pathologic cycles of scratching and inflammation, prompting ongoing research in neuroinflammation in itch pathology.
View moreConclusions
- There has been significant progress in understanding the physiology of itch over the last decade.
- The sensory nervous system in the skin plays a crucial role in detecting a range of sensations, including itch.
- Histamine is a well-known mediator of itch, but many itch pathways are histamine-independent.
- Recent research has identified numerous pruritogens and receptors that mediate itch beyond histamine, particularly involving free nerve endings like C fibers.
- Mouse models have been useful in understanding itch pathways and mediators, and there are parallels in human pruriceptors.
- Polymodal pruriceptors present in humans can respond to various stimuli, including itch and pain, indicating their complexity.
- Effective therapies for chronic itch, such as JAK inhibitors and monoclonal antibodies targeting IL-31, have been developed and shown to be effective in clinical trials.
- Scratching can provide immediate relief from itching but may trigger further inflammatory responses in the skin, complicating the condition.
- The intersection of itch and inflammation highlights that itching serves as a signal of underlying inflammation in the body.
- Advances in understanding itch biology pave the way for novel therapeutic strategies to manage chronic itch conditions.
- Tamari and Ver Heul et al. Ann Rev Immunol 2021
- Mu et al. Science 2017
- Mishra et al. Cell 2013
- Sun and Chen Nature 2007
- Liu et al. Cell 2009
- Han et al. Nat Neuro 2013
- Sonkoly et al. JACI 2006
- Usoskin et al. Nat Neurosci 2015
- Oejten et al. Cell 2017
- Cevikbas et al. JACI 2014
- Solinski et al. Cell Rep 2019
- Wang et al. Immunity 2019
- Kim et al. Cell 2024
- Nguyen et al. eLife 2021
- Trier et al. J Immunol 2019
- Kabashima et al. NEJM 2020
- Yosipovitch et al. Nat Med 2023
- Jeon et al. J Dermatol Treat 2021
- Wang et al. JAMA Dermatol 2019
- Flayer et al. Nature 2024
- Auyeung et al. Anna Allergy Asthma Immunol 2023