To save the Dr. visit he NEEDS to take Benadryl. If he has already he needs to take x2's the recommended dose. When you walk into the ER/urgent care having a reaction they give you a shot of liquid Benadryl that is higher than x2 the recommended dose. The tech told me If I would have simply upped my dosage and wait a short while I would have probably been fine...
Now for some hard truths. These reactions are VERY serious. I also agree that having this happen from beer is highly improbable. These reactions are caused by proteins your body think are harmful. In the case of the beer, his liver would have filtered it out and the proteins would have left his body to the tune of 1 average strength beer an hour or he evacuated the beer from his body naturally.
As this has been going on for days it could be a food reaction that he has been eating (EXAMPLE:cheap eggs or milk for breakfast) but I will bet it is a reaction to some sort of soap (laundry, hand, body, liquid fabric softener or dish.) The reason I think this is his skin is in contact with this for a much longer period of time. Ask him his wife/significant other if they have recently used ANY different soaps body, laundry, fab softener and dish. This is a MUCH more likely scenario than a reaction from the beer.
We had to give away all our soaps and buy the "free and clear" soaps because we think that was the cause of MY reaction. The reason I have not gone in for allergy tests is because I do not have insurance and it is a "best guess" system that requires MANY visits. Swapping out ALL the soaps has fixed my issue and was fairly cheap to try. If your friend does this and the hives do not go away, he starts having problems breathing he needs to see a Dr. ASAP.
I hope he feels better soon and that this helps.