Itch is an evolutionarily conserved sensation in vertebrates, and in its acute form, elicits a scratching reflex to expel environmental irritants such as insects, parasites, and toxins. However, in its chronic form, itch becomes highly debilitating and pathologic. Although originally considered a mild form of pain, the discovery of itch-specific molecular and cellular pathways in the last 15 years have greatly emboldened itch biology as a distinct field of inquiry (Wang and Kim, 2020). Furthermore, the unprecedented success of numerous therapeutics in this nascent field has drawn tremendous interest in solving the central symptom of itch across a number of medical disorders.
