Scientists have determined that chronic itch and pain are perceived differently by the brain and travel along different nerve pathways, report UTMB’s Norbert Herzog and David Niesel in this week’s installment of Medical Discovery News. The most common type of itch is caused by the chemical histamine, released by immune cells, but there is a second type of itch that is chronic and debilitating because, unlike the common itch, it is not treatable with a simple topical ointment. Confirming pain and itch sensations use separate nerve pathways will make treatment for chronic itch easier. MDN airs locally at 10 a.m. Saturday on KUHF.