Well see the thing is...the rash happens most often without a condom. I know its not the brilliant choice but birth control was being used so it wasn't totally irresponsible. I can only recall it happening once with a condom. But I've had this rash appear with two different woman, so that just leads me to believe it might have something to do with maybe a reaction to pH or something. As for the swelling, it did happen one other time, but it was only on one spot of my shaft and it was very itchy. This time it was the whole shaft but there was no itch. Then again, the first time it swelled, my bottom lip had also swelled, leading me to believe it might have been some form of allergic reaction. This time I had not eaten anything at all that day, I think maybe had a glass of OJ. But I've drank it since with no reactions. I'm just as lost as the next person
If you are using condoms or some type of lubricant you could be allergic to it. It is also possible to be allergic to another person. Try keeping a diary of when it happens and what was used or not used. Then you can narrow it down.