What are the causes and symptoms of itching?
The biology underlying itching is not fully understood. It is believed that itching results from the interactions of several different chemical messengers. Although itching and pain sensations were at one time thought to be sent along the same nerve pathways, researchers reported the discovery in 2003 of itch-specific nerve pathways. Nerve endings that are specifically sensitive to itching have been named pruriceptors. Research into itching has been helped by the recent invention of a mechanical device called the Matcher, which electrically stimulates the patient’s left hand. When the intensity of the stimulation equals the intensity of itching that the patient is experiencing elsewhere in the body, the patient stops the stimulation and the device automatically records the measurement. The Matcher was found to be sensitive to immediate changes in the patient’s perception of itching as well as reliable in its measurements. Stress and emotional upset can make itching worse, no matter wha
