50-yo obese male with high blood pressure and 25-pack-year s…

50-yo obese male with high blood pressure and 25-pack-year smoking history presents to your clinic complaining of severe burning in the feet for the past 6 months. Denies any recent injury or trauma. Denies any fevers, nausea, vomiting, chills or sweats. No improvement with OTC analgesics.  PE reveals a well-groomed, obese male with mild edema in the distal BLE. BLE ROM, strength and reflexes are all WNL. There is decreased sensation in the feet from light touch to hyperalgesia and sharp sensation in the feet. No evidence of erythema or open wounds. What is the likely source of this patient’s pain?

An 8-yo girl is running around her backyard when she trips a…

An 8-yo girl is running around her backyard when she trips and hits her elbow on the ground. She immediately gets up crying and runs to her mother who instinctively starts to rub the elbow to console her daughter. Without even knowing it, mom is stimulating the A-beta fibers and reducing substance P, thus lowering the pain signal. What is this concept known as?