Thank You...My Husband (age 80) Has A Swollen Index Finger.

Thank you...My husband (age 80) has a swollen index finger. It is red. He said it started yesterday, but did not tell me until now!! He does not remember doing anything, or doesn't think there is a splinter. I am wondering about an insect bite...there seems to be a "dot". Years ago he had a foot puff up due to a bite. He has controlled AFib. The wind chill is -22 here and I wonder if a Tylenol (or Benadryl) and ice would be proper treatment. It is not throbbing, no streaks, no real pain, just stiff. He does not have any other swollen or painful areas. I don't think this is an emergency, but need recommendation. Thanks Lois Peterson Rockford, IL