What Causes A Nasal Swelling In An Autistic Male?

Hi, I'm trying to figure out what swelling on each side of my sons nose and a little at the bridge of his nose could be. He is pushing on his eyes constantly. He is autistic-completely non-verbal. He is 19 years old. He is taking Tenex. 2mg. a day, down from 4 mg. a month ago. He takes one A.M. one P.M. He is also just getting off lithium as of a month ago. He was on 1200 mg. daily. He has had a cat scan that was negative for sinus issues. Thank you, Denise