big red bump on dog's lip

[threezero]

sigh so I finally figure out what was causing allergy to my shepherd a while back that cause him to have little red bumps all over his stomach. Switch his diet and all seem fine. That is until I went on a few day trip my boy was being taken care of by my parents. When i come back I notice a very big red swelling bump on his bottom lip, no discomfort when i squeeze it and the surface of the bump appears to be smooth. It is very alarming, to me it looks like a huge acne but upon close inspection the bottom of his lip seems to be very red and swollen. he did like to rub his nose against out wall of furniture i assume that was because soemthing tickle his nose now could this be related.

I have put some antibiotic cream on the bump hoping it will get better if not I will likely take him to the vet but that is going to be a very tramatic experience for him, he might need to be heavily sedated or tranquilized for the vet to examine his lip. has anybody else's dog had something like this? could this only be acne? doggie herpe virus? my boy rarely if even interact with other dogs and he certainly didn't lick no dirty bitch's puss recently. if anybody have any idea plz do share. seems to be a bad year for my dog, annoying allergy problem, rip an entire nail off his feet and now this, sigh.......

[Lil Bastrd]

redness and swelling aren't usually an acne related thing. I could be entirely wrong if the dog has been scratching or rubbing the spot it could have aggravated it. acne is usually small bumps around the muzzle and nose.

[threezero]

yea he has a habit of rubbing his whole face on things, could this also possibly be allergy related? after applying antibiotic cream on it for 2 days the swelling is less and that huge bump has shrink so what. is it possible for a tumor to erupt in like 4 days?