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Updated: Jan 24, 2026

Cheek Injection Model for Simultaneous Measurement of Pain and Itch-related Behaviors
Published on: September 27, 2019
The Itch-Scratch Cycle: A Review of the Mechanisms
1St. George's University & Hospital of London, UK.
Background:
Despite being one of the most common presenting dermatological symptoms, itching continues to perplex health care professionals because it is notoriously difficult to control.
Objective:
This review gathers evidence to answer the 2-part question, "Why do we itch and scratch?" by exploring the history of itchy disease, the neurobiology of itch, and the 4 different clinical origins of itch: pruritogenic, neurological, neuropathic, and psychological.
Results:
The automated scratching reflex and its biological and psychological reasons for existence are complicated and poorly understood. Currently, there are a myriad of treatments available for individuals suffering from this condition; however, many remain symptomatic.
Conclusions:
The itch-scratch cycle is a complex pain-like sensation with a reflex-like response. In the future, continued exploration into the mechanisms behind itch and scratch may open the doors for new therapeutic interventions.
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