Since Christmas 88 year old dad has sore tongue, says tastes like oil or metal sometimes. Nose sometimes sore. Throat off and on sore, sometimes red, swollen a bit, more often last 2 weeks. Has had one or combination of these symptoms almost 2 months daily basis. Tongue/throat not coated, normal appearing except slightly red sometimes. No fever. Varies in severity. Generally good health. Has unusual RBC MCV (genetic)-wondered about anemia but why the sore throat? Went to doctor and referred to specialist but Dad so far has not gone. Tested negative for strep. Only test done. Got him an ultrasonic neb in case dry air causing this. Using air cleaner. Seems to feel better when outside of the house for a while in the cold air but cannot determine what may be different in home lived in for 60 years. No new meds. Had similar episode 20 years ago when had fuel oil tank for furnace in basement. Removed that then and switched to propane with tank outside. It resolved then. Not sure if cause or had just run its course - wondered if propane grade may have deteriorated and causing some fumes, but I cannot smell anything. He lives alone. Any help much appreciated.