My Husband Is C\o His Throat Feels Like It Is

My husband is c\o his throat feels like it is swelling. He can drink fine but feels tight. the back of his throat is slightly red. He says it does not feel like a cold but his has been around our 11 year old grandson who has had one. I gave him 25mg of benadryl to see if this would help a few hours ago and plan on taking him in to Patient first in the morning.